Pub Date : 2023-09-06DOI: 10.1088/1361-6641/acf72e
Yunkai Li, Siqi Zhao, Shangyue Yang, Ning Guo, Weilong Yuan, Y. Pei, Guoguo Yan, Xingfang Liu
Low-temperature post oxidation annealing of 4H-SiC at 900 °C for 90 min after photoelectric chemical (PEC) etching in alkaline solution can eliminate the porous structures that form during the etching process, reduce the porosity, and optimize the surface morphology, which has minimal effect on unetched surfaces, allowing for selective treatment between etched and unetched surfaces. Additionally, it can improve the etching depth and enable effective repetition of the etching process. These benefits make PEC etching a valuable technique for microstructure fabrication and surface treatment.
{"title":"Selective removal of 4H-SiC porous structures caused by photoelectric chemical etching via post oxidation annealing","authors":"Yunkai Li, Siqi Zhao, Shangyue Yang, Ning Guo, Weilong Yuan, Y. Pei, Guoguo Yan, Xingfang Liu","doi":"10.1088/1361-6641/acf72e","DOIUrl":"https://doi.org/10.1088/1361-6641/acf72e","url":null,"abstract":"Low-temperature post oxidation annealing of 4H-SiC at 900 °C for 90 min after photoelectric chemical (PEC) etching in alkaline solution can eliminate the porous structures that form during the etching process, reduce the porosity, and optimize the surface morphology, which has minimal effect on unetched surfaces, allowing for selective treatment between etched and unetched surfaces. Additionally, it can improve the etching depth and enable effective repetition of the etching process. These benefits make PEC etching a valuable technique for microstructure fabrication and surface treatment.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48903335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The properties of a minority carrier (hole) trap in β-Ga2O3 have been explicitly investigated using a NiO/β-Ga2O3 p–n heterojunction. Via deep-level transient spectroscopy, the activation energy for emission (E emi) and the hole capture cross section (σp ) were derived to be 0.10 eV and 2.48 × 10−15 cm2, respectively. Temperature-enhanced capture and emission kinetics were revealed by the decrease in the capture time constant (τc ) and emission time constant (τe ). Moreover, it was determined that the emission process of the minority carrier trap is independent of the electric field. Taking carrier recombination into account, a corrected trap concentration (N Ta) of 2.73 × 1015 cm−3 was extracted, together with an electron capture cross section (σn ) of 1.42 × 10−18 cm2. This study provides a foundation for the comprehension of trap properties in β-Ga2O3, which is crucial for overcoming self-trapped hole effects when obtaining p-type β-Ga2O3 materials and performance enhancement of β-Ga2O3-based power devices.
{"title":"Investigation of a minority carrier trap in a NiO/β-Ga2O3 p–n heterojunction via deep-level transient spectroscopy","authors":"Haolan Qu, Jiaxiang Chen, Yu Zhang, Jin-chi Sui, Ruohan Zhang, Junmin Zhou, Xing Lu, Xinbo Zou","doi":"10.1088/1361-6641/acf608","DOIUrl":"https://doi.org/10.1088/1361-6641/acf608","url":null,"abstract":"The properties of a minority carrier (hole) trap in β-Ga2O3 have been explicitly investigated using a NiO/β-Ga2O3 p–n heterojunction. Via deep-level transient spectroscopy, the activation energy for emission (E emi) and the hole capture cross section (σp ) were derived to be 0.10 eV and 2.48 × 10−15 cm2, respectively. Temperature-enhanced capture and emission kinetics were revealed by the decrease in the capture time constant (τc ) and emission time constant (τe ). Moreover, it was determined that the emission process of the minority carrier trap is independent of the electric field. Taking carrier recombination into account, a corrected trap concentration (N Ta) of 2.73 × 1015 cm−3 was extracted, together with an electron capture cross section (σn ) of 1.42 × 10−18 cm2. This study provides a foundation for the comprehension of trap properties in β-Ga2O3, which is crucial for overcoming self-trapped hole effects when obtaining p-type β-Ga2O3 materials and performance enhancement of β-Ga2O3-based power devices.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44933635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.1088/1361-6641/acf59b
E. McVay, R. Deri, W. Fenwick, S. Baxamusa, Jiang Li, N. Allen, D. Mittelberger, R. Swertfeger, S. Telford, M. Boisselle, D. Pope, D. Dutra, Logan Martin, Laina V. Gilmore, G. Thaler, M. Crowley, Jiyon Song, P. Thiagarajan
A method for determination of non-radiative carrier lifetimes in the waveguide and active regions of quantum well laser diodes is presented. This method is suitable for characterization of fully packaged devices and requires no special measurement equipment if the device structure is known. The proposed approach is experimentally demonstrated for several 800 nm laser diodes.
{"title":"Determination of nonradiative carrier lifetimes in quantum well laser diodes from subthreshold characteristics","authors":"E. McVay, R. Deri, W. Fenwick, S. Baxamusa, Jiang Li, N. Allen, D. Mittelberger, R. Swertfeger, S. Telford, M. Boisselle, D. Pope, D. Dutra, Logan Martin, Laina V. Gilmore, G. Thaler, M. Crowley, Jiyon Song, P. Thiagarajan","doi":"10.1088/1361-6641/acf59b","DOIUrl":"https://doi.org/10.1088/1361-6641/acf59b","url":null,"abstract":"A method for determination of non-radiative carrier lifetimes in the waveguide and active regions of quantum well laser diodes is presented. This method is suitable for characterization of fully packaged devices and requires no special measurement equipment if the device structure is known. The proposed approach is experimentally demonstrated for several 800 nm laser diodes.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48933465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-25DOI: 10.1088/1361-6641/acf406
Dan Zhang, Chun-ping Chen, M. Ren, Kewang Shi, Jin Huang
All-inorganic CsPbI3 perovskite solar cells (PSCs) technology is gradually maturing because of its excellent photoelectric characteristics. However, the hysteresis phenomenon induced by ion migration in the perovskite film not only seriously affects the performance of the device, but also accelerates the degradation of the film, which limits the further improvement of power conversion efficiency (PCE) for CsPbI3 PSCs. Herein, in this paper, a new inorganic fluorine-containing additive rubidium fluoride (RbF) was introduced as a precursor additive. The incorporation of RbF effectively improved the crystallization kinetics of CsPbI3 perovskite film and effectively suppressed the occurrence of hysteresis. The defects on the CsPbI3 perovskite film are remarkably inhibited and the carrier dynamics process is greatly promoted with the incorporation of 0.03 mol% RbF. In addition, the non-radiative recombination is significantly suppressed, and the device stability is substantially improved. In particular, by doping 0.03 mol% RbF into the CsPbI3, the hysteresis index of PSCs decreases to 0.003. The introduction of RbF effectively improves the device performance, and the highest efficiency has reached to 17.21%. The environmental stability has also been significantly enhanced with the RbF doping.
{"title":"Rubidium fluoride additive for high-efficiency and low-hysteresis all-inorganic CsPbI3 perovskite solar cells","authors":"Dan Zhang, Chun-ping Chen, M. Ren, Kewang Shi, Jin Huang","doi":"10.1088/1361-6641/acf406","DOIUrl":"https://doi.org/10.1088/1361-6641/acf406","url":null,"abstract":"All-inorganic CsPbI3 perovskite solar cells (PSCs) technology is gradually maturing because of its excellent photoelectric characteristics. However, the hysteresis phenomenon induced by ion migration in the perovskite film not only seriously affects the performance of the device, but also accelerates the degradation of the film, which limits the further improvement of power conversion efficiency (PCE) for CsPbI3 PSCs. Herein, in this paper, a new inorganic fluorine-containing additive rubidium fluoride (RbF) was introduced as a precursor additive. The incorporation of RbF effectively improved the crystallization kinetics of CsPbI3 perovskite film and effectively suppressed the occurrence of hysteresis. The defects on the CsPbI3 perovskite film are remarkably inhibited and the carrier dynamics process is greatly promoted with the incorporation of 0.03 mol% RbF. In addition, the non-radiative recombination is significantly suppressed, and the device stability is substantially improved. In particular, by doping 0.03 mol% RbF into the CsPbI3, the hysteresis index of PSCs decreases to 0.003. The introduction of RbF effectively improves the device performance, and the highest efficiency has reached to 17.21%. The environmental stability has also been significantly enhanced with the RbF doping.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44784867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-25DOI: 10.1088/1361-6641/acf407
Ze Li, Guodong Yuan, Di Zhang, Yumeng Liu, Haoran Long, Li He, Dechen Wang, Zhongming Wei, Junwei Luo
Quantum computing is expected to break the computing power bottleneck with the help of quantum superposition and quantum entanglement. In order to fabricate fault-tolerant quantum computers for encoding quantum information, it is important to improve the cryogenic mobility of silicon-based metal oxide semiconductor field effect transistors (MOSFETs) with a thin gate dielectric layer as much as possible. Based on a thin SiO2/HfO2 stacked dielectric, we investigate the effect of post-deposition annealing (PDA) temperature on the MOSFET cryogenic transport properties. The results show that silicon atoms will diffuse into the HfO2 to form silicates during PDA, leading to the HfO2 dielectric constant decrease. As the PDA temperature increases, the proportion of monoclinic hafnium oxide decreases and the tetragonal phase increases gradually. The oxygen vacancy content increases gradually, resulting in fixed charge density increases and the mobility decreases. The contribution of the forming gas annealing (FGA) to the mobility enhancement is clarified and the HfO2 recrystallization process is revealed from the perspective of long-time annealing. Finally, the mobility peak of silicon MOSFETs with thin SiO2/HfO2 dielectrics is enhanced to 1387 cm2(V·s)−1 at 1.6 K, which provides a technical pathway for the development of silicon-based quantum computation.
{"title":"Effect of high temperature annealing on cryogenic transport properties of silicon MOSFETs with a thin SiO2/HfO2 stacked dielectric","authors":"Ze Li, Guodong Yuan, Di Zhang, Yumeng Liu, Haoran Long, Li He, Dechen Wang, Zhongming Wei, Junwei Luo","doi":"10.1088/1361-6641/acf407","DOIUrl":"https://doi.org/10.1088/1361-6641/acf407","url":null,"abstract":"Quantum computing is expected to break the computing power bottleneck with the help of quantum superposition and quantum entanglement. In order to fabricate fault-tolerant quantum computers for encoding quantum information, it is important to improve the cryogenic mobility of silicon-based metal oxide semiconductor field effect transistors (MOSFETs) with a thin gate dielectric layer as much as possible. Based on a thin SiO2/HfO2 stacked dielectric, we investigate the effect of post-deposition annealing (PDA) temperature on the MOSFET cryogenic transport properties. The results show that silicon atoms will diffuse into the HfO2 to form silicates during PDA, leading to the HfO2 dielectric constant decrease. As the PDA temperature increases, the proportion of monoclinic hafnium oxide decreases and the tetragonal phase increases gradually. The oxygen vacancy content increases gradually, resulting in fixed charge density increases and the mobility decreases. The contribution of the forming gas annealing (FGA) to the mobility enhancement is clarified and the HfO2 recrystallization process is revealed from the perspective of long-time annealing. Finally, the mobility peak of silicon MOSFETs with thin SiO2/HfO2 dielectrics is enhanced to 1387 cm2(V·s)−1 at 1.6 K, which provides a technical pathway for the development of silicon-based quantum computation.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48508985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-24DOI: 10.1088/1361-6641/acf396
D. Chen, Axel R. Persson, V. Darakchieva, P. O. Persson, Jr-Tai Chen, N. Rorsman
This study presents a novel approach to forming low-resistance ohmic contacts for AlGaN/GaN HEMTs. The optimized contacts exhibit an outstanding contact resistance of approximately 0.15 Ω·mm. This is achieved by firstly recessing the barrier of the heterostructure to a depth beyond the channel. In this way, the channel region is exposed on the sidewall of the recess. The coverage of the Ti/Al/Ti ohmic metalization on the sidewall is ensured through tilting of the sample during evaporation. The annealing process is performed at a low temperature of 550 °C. The approach does not require precise control of the recess etching. Furthermore, the method is directly applicable to most barrier designs in terms of thickness and Al-concentration. The impact of recessed sidewall angle, thickness and ratio of Ti and Al layers, and the annealing procedure are investigated. Structural and chemical analyses of the interface between the ohmic contacts and epi-structure indicate the formation of ohmic contacts by the extraction of nitrogen from the epi-structure. The approach is demonstrated on HEMT-structures with two different barrier designs in terms of Al-concentration and barrier thickness. The study demonstrate large process window in regard to recess depth and duration of the annealing as well as high uniformity of the contact resistance across the samples, rendering the approach highly suitable for industrial production processes.
{"title":"Structural investigation of ultra-low resistance deeply recessed sidewall ohmic contacts for AlGaN/GaN HEMTs based on Ti/Al/Ti-metallization","authors":"D. Chen, Axel R. Persson, V. Darakchieva, P. O. Persson, Jr-Tai Chen, N. Rorsman","doi":"10.1088/1361-6641/acf396","DOIUrl":"https://doi.org/10.1088/1361-6641/acf396","url":null,"abstract":"This study presents a novel approach to forming low-resistance ohmic contacts for AlGaN/GaN HEMTs. The optimized contacts exhibit an outstanding contact resistance of approximately 0.15 Ω·mm. This is achieved by firstly recessing the barrier of the heterostructure to a depth beyond the channel. In this way, the channel region is exposed on the sidewall of the recess. The coverage of the Ti/Al/Ti ohmic metalization on the sidewall is ensured through tilting of the sample during evaporation. The annealing process is performed at a low temperature of 550 °C. The approach does not require precise control of the recess etching. Furthermore, the method is directly applicable to most barrier designs in terms of thickness and Al-concentration. The impact of recessed sidewall angle, thickness and ratio of Ti and Al layers, and the annealing procedure are investigated. Structural and chemical analyses of the interface between the ohmic contacts and epi-structure indicate the formation of ohmic contacts by the extraction of nitrogen from the epi-structure. The approach is demonstrated on HEMT-structures with two different barrier designs in terms of Al-concentration and barrier thickness. The study demonstrate large process window in regard to recess depth and duration of the annealing as well as high uniformity of the contact resistance across the samples, rendering the approach highly suitable for industrial production processes.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42966128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-24DOI: 10.1088/1361-6641/acf397
Depi Oktapia, E. Nurfani, B. Wahjoedi, Lukman Nulhakim, Granprix T M Kadja
In this paper, we study the effect of solution pH in the hydrothermal synthesis and post-annealing treatment on the photocatalytic performance of hexagonal prism ZnO grown without a seed layer. By varying the precursor molarity ratio, the solution obtained was 6.88 (ZnO-2), 7.00 (ZnO-1), and 7.58 (ZnO-3). The three samples show hexagonal prism ZnO with wurtzite structures based on scanning electron microscope and x-ray diffraction analysis. ZnO-1 samples could degrade methylene blue as high as 65.9% for a UV irradiation time of 5 h, better than ZnO-2 (51.80%) and ZnO-3 (57.55%). Post-annealing treatment of ZnO-1 with the best photodegradation efficiency was carried out at 200 °C (ZnO-4) and 400 °C (ZnO-5) to alter the structure. The post-annealing treatment changes the domination of crystal orientation from (002) to (100) plane. Also, the morphology of ZnO-5 changed significantly to become smaller rods with a diameter of 2.79 μm, as compared to ZnO-1 (2.83 μm) and ZnO-4 (3.12 μm). It is due to ionic rearrangements occurring at higher temperatures. The ZnO-5 sample reduces methylene blue by 82.91%, which is better than ZnO-1 (65.9%) and ZnO-4 (64.39%). Interestingly, we found a relation between smaller rod diameters and higher photocatalytic activity. The results show the importance of the solution pH and the annealing treatment in improving the photocatalytic performance of hexagonal prism ZnO without the seed layer.
{"title":"Seedless hydrothermal growth of hexagonal prism ZnO for photocatalytic degradation of methylene blue: the effect of pH and post-annealing treatment","authors":"Depi Oktapia, E. Nurfani, B. Wahjoedi, Lukman Nulhakim, Granprix T M Kadja","doi":"10.1088/1361-6641/acf397","DOIUrl":"https://doi.org/10.1088/1361-6641/acf397","url":null,"abstract":"In this paper, we study the effect of solution pH in the hydrothermal synthesis and post-annealing treatment on the photocatalytic performance of hexagonal prism ZnO grown without a seed layer. By varying the precursor molarity ratio, the solution obtained was 6.88 (ZnO-2), 7.00 (ZnO-1), and 7.58 (ZnO-3). The three samples show hexagonal prism ZnO with wurtzite structures based on scanning electron microscope and x-ray diffraction analysis. ZnO-1 samples could degrade methylene blue as high as 65.9% for a UV irradiation time of 5 h, better than ZnO-2 (51.80%) and ZnO-3 (57.55%). Post-annealing treatment of ZnO-1 with the best photodegradation efficiency was carried out at 200 °C (ZnO-4) and 400 °C (ZnO-5) to alter the structure. The post-annealing treatment changes the domination of crystal orientation from (002) to (100) plane. Also, the morphology of ZnO-5 changed significantly to become smaller rods with a diameter of 2.79 μm, as compared to ZnO-1 (2.83 μm) and ZnO-4 (3.12 μm). It is due to ionic rearrangements occurring at higher temperatures. The ZnO-5 sample reduces methylene blue by 82.91%, which is better than ZnO-1 (65.9%) and ZnO-4 (64.39%). Interestingly, we found a relation between smaller rod diameters and higher photocatalytic activity. The results show the importance of the solution pH and the annealing treatment in improving the photocatalytic performance of hexagonal prism ZnO without the seed layer.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47657777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-22DOI: 10.1088/1361-6641/acf2be
H.I. Solís-Cisneros, H. Vilchis, Raúl Hernández-Trejo, Ana L. Melchor-Tovilla, Á. Guillén-Cervantes, Carlos A Hernández Gutiérrez
In this work, we present the characterization of a UV-sensitive material based on Ga2O3-GaOOH, which was obtained through the thermal oxidation of GaAs wafers in ambient air to achieve Ga2O3. The material’s oxidation mechanism was thoroughly examined using structural, compositional, and optical approaches. X-ray diffraction analysis identified the presence of the β-Ga2O3 crystalline phase, with both in-plane and out-of-plane preferred orientations, along with crystalline inclusions attributed to GaOOH. Furthermore, energy-dispersive spectroscopy confirmed the uniform sublimation of Arsenic, as evidenced by elemental mapping, while Fourier-transform infrared spectroscopy suggested the inclusion of −OH bonds. Surface analysis was carried out by field emission scanning electron microscopy and atomic force microscopy, revealing a grain size of approximately 20 nm. Finally, UV-Vis characterization unveiled a bandgap ranging from 2.9 to 3.9 eV, indicative of the material’s potential for UV-sensitive applications. Overall, the results demonstrate the consistency and reliability of the oxidation process, providing valuable insights into the properties of the Ga2O3-GaOOH material for potential technological advancements.
{"title":"Study and characterization of the nanotextured Ga2O3-GaOOH formations synthesized via thermal oxidation of GaAs in ambient air","authors":"H.I. Solís-Cisneros, H. Vilchis, Raúl Hernández-Trejo, Ana L. Melchor-Tovilla, Á. Guillén-Cervantes, Carlos A Hernández Gutiérrez","doi":"10.1088/1361-6641/acf2be","DOIUrl":"https://doi.org/10.1088/1361-6641/acf2be","url":null,"abstract":"In this work, we present the characterization of a UV-sensitive material based on Ga2O3-GaOOH, which was obtained through the thermal oxidation of GaAs wafers in ambient air to achieve Ga2O3. The material’s oxidation mechanism was thoroughly examined using structural, compositional, and optical approaches. X-ray diffraction analysis identified the presence of the β-Ga2O3 crystalline phase, with both in-plane and out-of-plane preferred orientations, along with crystalline inclusions attributed to GaOOH. Furthermore, energy-dispersive spectroscopy confirmed the uniform sublimation of Arsenic, as evidenced by elemental mapping, while Fourier-transform infrared spectroscopy suggested the inclusion of −OH bonds. Surface analysis was carried out by field emission scanning electron microscopy and atomic force microscopy, revealing a grain size of approximately 20 nm. Finally, UV-Vis characterization unveiled a bandgap ranging from 2.9 to 3.9 eV, indicative of the material’s potential for UV-sensitive applications. Overall, the results demonstrate the consistency and reliability of the oxidation process, providing valuable insights into the properties of the Ga2O3-GaOOH material for potential technological advancements.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43824160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-21DOI: 10.1088/1361-6641/acf241
Y. Oshima, T. Oshima
We demonstrated halide vapor phase epitaxy of β-Ga2O3 on a native 1ˉ02 substrate, which should be scalable and useful for the formation of vertical fins and trenches with smooth (100)-faceted sidewalls using plasma-free microfabrication techniques, e.g., selective area growth and gas etching, for use in power device applications. No misoriented domains were detected in the epiwafer during x-ray pole figure measurements. The full width at half maximum values of the x-ray rocking curves of the epiwafer were virtually the same as those of the bare substrate. No domain boundaries were found using scanning transmission electron microscopy at the film/substrate interface. The growth rate was as high as 23 μm h−1, which was comparable to the rate for a (001) epilayer that was grown simultaneously.
{"title":"Homoepitaxial growth of 1ˉ02 β-Ga2O3 by halide vapor phase epitaxy","authors":"Y. Oshima, T. Oshima","doi":"10.1088/1361-6641/acf241","DOIUrl":"https://doi.org/10.1088/1361-6641/acf241","url":null,"abstract":"We demonstrated halide vapor phase epitaxy of β-Ga2O3 on a native 1ˉ02 substrate, which should be scalable and useful for the formation of vertical fins and trenches with smooth (100)-faceted sidewalls using plasma-free microfabrication techniques, e.g., selective area growth and gas etching, for use in power device applications. No misoriented domains were detected in the epiwafer during x-ray pole figure measurements. The full width at half maximum values of the x-ray rocking curves of the epiwafer were virtually the same as those of the bare substrate. No domain boundaries were found using scanning transmission electron microscopy at the film/substrate interface. The growth rate was as high as 23 μm h−1, which was comparable to the rate for a (001) epilayer that was grown simultaneously.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48139175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-15DOI: 10.1088/1361-6641/acf06b
Liangliang Tang, Long Yin, J. Shao, Yili Tang, Yonghui Liu
InGaAs cells are ideal converters for low temperature thermophotovoltaic power generation systems. Commonly, the positive and negative electrodes of InGaAs cells are deposited on the top and bottom of the cells, respectively. In the engineering of level modules, solder strips are used to connect the top and bottom of adjacent cells, the distance between the cells is considerable in order to prevent short circuits from the side wall of the cells, and the area ratio of cells to modules is relatively low. In this paper, we design and fabricate a novel all-top-contact InGaAs cell, with the positive electrode deposited on top of the p-InGaAs epitaxial layer, and the negative electrode deposited on top of the n-InPAs-grade epitaxial layer by precise etching of the p–n junction layers. The novel all-top-contact cells show good efficiencies compared to traditional cells with top-and-bottom electrodes under the same testing conditions. Novel flat and compact cell modules were fabricated using all-top-contact InGaAs cells, the distance between the adjacent cells was controlled within tens of microns, and the area ratio of cells to modules was improved efficiently.
{"title":"All-top-contact 0.59 eV InGaAs thermophotovoltaic cells and modules","authors":"Liangliang Tang, Long Yin, J. Shao, Yili Tang, Yonghui Liu","doi":"10.1088/1361-6641/acf06b","DOIUrl":"https://doi.org/10.1088/1361-6641/acf06b","url":null,"abstract":"InGaAs cells are ideal converters for low temperature thermophotovoltaic power generation systems. Commonly, the positive and negative electrodes of InGaAs cells are deposited on the top and bottom of the cells, respectively. In the engineering of level modules, solder strips are used to connect the top and bottom of adjacent cells, the distance between the cells is considerable in order to prevent short circuits from the side wall of the cells, and the area ratio of cells to modules is relatively low. In this paper, we design and fabricate a novel all-top-contact InGaAs cell, with the positive electrode deposited on top of the p-InGaAs epitaxial layer, and the negative electrode deposited on top of the n-InPAs-grade epitaxial layer by precise etching of the p–n junction layers. The novel all-top-contact cells show good efficiencies compared to traditional cells with top-and-bottom electrodes under the same testing conditions. Novel flat and compact cell modules were fabricated using all-top-contact InGaAs cells, the distance between the adjacent cells was controlled within tens of microns, and the area ratio of cells to modules was improved efficiently.","PeriodicalId":21585,"journal":{"name":"Semiconductor Science and Technology","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43218746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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