Pub Date : 2018-12-01DOI: 10.1109/icee44586.2018.8937960
A. K. Jagdish, M. P. Kumar, B. S. Sandeep, Praveen C Ramamurthy, D. Mahapatra, G. Hegde
Hierarchical structures comprise of patterns which are themselves structured at lower length scales. Such structures can outperform the performance limits posed by continuum and non-hierarchical structures. However, the possible role of hierarchical structuring in photonics and optoelectronics are not well understood. Here we report on the implications of using materials structured at multiple length scales in the design of spectrally uniform photodetectors. We present our results on the design and fabrication of hierarchical structures comprising of alternating planar and nanostructured microscale domains interspersed with nanoscale objects. These structures show the possibility of obtaining unusual control over the flow of light compared to conventional non-hierarchical structures through the coupling of light across micro-domains. These multiscale structures are fabricated using self-assembly and a novel mechanical strain-augmented template based nano-molding process. We fabricate multi-periodic nanostructures embedded in a random distribution of micro-domains, using an initial template which has only monoperiodic structures. Organic photodetectors fabricated on these molded multiscale platforms show considerable improvements in spectral uniformity. This design advantage arises through the multiscale optical processes which preferentially filter light entering the absorber, which occur only in a hierarchically structured device. In summary, this paper explores unusual ways to control the flow of light using hierarchical structures. On the optoelectronic design front, hierarchical structures are seen to improve the spectral uniformity of photodetectors beyond the limits of continuum and non-hierarchical material design. Further, this effort pushes the limits of monodisperse self-assembly to fabricate static multiperiodic structures, using facile mechanical strain augmented nanofabrication, which was hitherto a challenge.
{"title":"Hierarchical structures and multiscale optical coupling for improved photodetectors","authors":"A. K. Jagdish, M. P. Kumar, B. S. Sandeep, Praveen C Ramamurthy, D. Mahapatra, G. Hegde","doi":"10.1109/icee44586.2018.8937960","DOIUrl":"https://doi.org/10.1109/icee44586.2018.8937960","url":null,"abstract":"Hierarchical structures comprise of patterns which are themselves structured at lower length scales. Such structures can outperform the performance limits posed by continuum and non-hierarchical structures. However, the possible role of hierarchical structuring in photonics and optoelectronics are not well understood. Here we report on the implications of using materials structured at multiple length scales in the design of spectrally uniform photodetectors. We present our results on the design and fabrication of hierarchical structures comprising of alternating planar and nanostructured microscale domains interspersed with nanoscale objects. These structures show the possibility of obtaining unusual control over the flow of light compared to conventional non-hierarchical structures through the coupling of light across micro-domains. These multiscale structures are fabricated using self-assembly and a novel mechanical strain-augmented template based nano-molding process. We fabricate multi-periodic nanostructures embedded in a random distribution of micro-domains, using an initial template which has only monoperiodic structures. Organic photodetectors fabricated on these molded multiscale platforms show considerable improvements in spectral uniformity. This design advantage arises through the multiscale optical processes which preferentially filter light entering the absorber, which occur only in a hierarchically structured device. In summary, this paper explores unusual ways to control the flow of light using hierarchical structures. On the optoelectronic design front, hierarchical structures are seen to improve the spectral uniformity of photodetectors beyond the limits of continuum and non-hierarchical material design. Further, this effort pushes the limits of monodisperse self-assembly to fabricate static multiperiodic structures, using facile mechanical strain augmented nanofabrication, which was hitherto a challenge.","PeriodicalId":6590,"journal":{"name":"2018 4th IEEE International Conference on Emerging Electronics (ICEE)","volume":"69 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84989003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-01DOI: 10.1109/icee44586.2018.8937871
P. Suri, Preeti Deshpande, Ambarish Ghosh
We present a wafer scale, laser controlled fabrication method for making large-area, plasmonic dimeron-pillar configuration, using stimulated dewetting of thin silver film on MoS2 covered gold disc. The dewetting of 3-nmthick silver film forms preferential silver islands only on the exposed area of the samples. An enhancement in Raman signal is observed, implying the usage of said surface for surface enhanced Raman scattering (SERS). The fabricated configuration can act as a simple and convenient template for optoelectronic and photonic devices.
{"title":"Selective dewetting of metal films for fabrication of atomically separated nanoplasmonic dimers","authors":"P. Suri, Preeti Deshpande, Ambarish Ghosh","doi":"10.1109/icee44586.2018.8937871","DOIUrl":"https://doi.org/10.1109/icee44586.2018.8937871","url":null,"abstract":"We present a wafer scale, laser controlled fabrication method for making large-area, plasmonic dimeron-pillar configuration, using stimulated dewetting of thin silver film on MoS2 covered gold disc. The dewetting of 3-nmthick silver film forms preferential silver islands only on the exposed area of the samples. An enhancement in Raman signal is observed, implying the usage of said surface for surface enhanced Raman scattering (SERS). The fabricated configuration can act as a simple and convenient template for optoelectronic and photonic devices.","PeriodicalId":6590,"journal":{"name":"2018 4th IEEE International Conference on Emerging Electronics (ICEE)","volume":"33 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73316213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-01DOI: 10.1109/icee44586.2018.8937982
A. Lele, P. Kumbhare, U. Ganguly
Gradual synaptic weight change is a challenge for realistic RRAM, where SET is normally abrupt. Hence, an attractive RESET only learning scheme is demonstrated with a simple circuit implementation. However, the performance is highly sensitive to programming pulse and thus the RRAM characteristics. In this paper, we analyze the circuit implementation to show that performance sensitivity to RRAM programming is not fundamental. Our circuit analysis indicates that the winner-take-all (WTA) circuit malfunctions due to an insufficient time-resolution. Thus, the WTA circuit time-resolution needs to be co-optimized with RRAM and LIF neuron timescale. We experimentally measure a variety of programming characteristics of PCMO based RRAM by program-pulse engineering. We implement this strategy to demonstrate 100% performance irrespective of RRAM as opposed to previous work in a noisy angle learning and classification task. This essentially indicates that energy minimization of synaptic conductance change based on RRAM materials and pulse selection becomes the primary consideration - instead of RRAM gradual conductance change and range. Additionally, the constraint simplification leads to the reduction in energy consumption.
{"title":"Robust Unsupervised Two Layered Network with RRAM Synapses for Image Recognition","authors":"A. Lele, P. Kumbhare, U. Ganguly","doi":"10.1109/icee44586.2018.8937982","DOIUrl":"https://doi.org/10.1109/icee44586.2018.8937982","url":null,"abstract":"Gradual synaptic weight change is a challenge for realistic RRAM, where SET is normally abrupt. Hence, an attractive RESET only learning scheme is demonstrated with a simple circuit implementation. However, the performance is highly sensitive to programming pulse and thus the RRAM characteristics. In this paper, we analyze the circuit implementation to show that performance sensitivity to RRAM programming is not fundamental. Our circuit analysis indicates that the winner-take-all (WTA) circuit malfunctions due to an insufficient time-resolution. Thus, the WTA circuit time-resolution needs to be co-optimized with RRAM and LIF neuron timescale. We experimentally measure a variety of programming characteristics of PCMO based RRAM by program-pulse engineering. We implement this strategy to demonstrate 100% performance irrespective of RRAM as opposed to previous work in a noisy angle learning and classification task. This essentially indicates that energy minimization of synaptic conductance change based on RRAM materials and pulse selection becomes the primary consideration - instead of RRAM gradual conductance change and range. Additionally, the constraint simplification leads to the reduction in energy consumption.","PeriodicalId":6590,"journal":{"name":"2018 4th IEEE International Conference on Emerging Electronics (ICEE)","volume":"4 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75373095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-01DOI: 10.1109/icee44586.2018.8937953
M. Anuja Menokey, A. Ajoy
In this paper, we introduce an analytical surface potential based model for sheet carrier density and current in N-polar GaN/AlN/AlGaN metal insulator semiconductor high electron mobility transistors (MIS-HEMTs). The proposed sheet carrier density model is derived in terms of Fermi-level $(E_{f})$, gate potential $(V_{g})$ and channel potential $(V_{c})$. The surface potential current model using charge control equations and high field saturation Canali mobility model are in close agreement with simulation and experimental data over a wide range of applied gate biases.
{"title":"A Surface-Potential Model for N-Polar GaN/AlN/AlGaN MIS-HEMTs","authors":"M. Anuja Menokey, A. Ajoy","doi":"10.1109/icee44586.2018.8937953","DOIUrl":"https://doi.org/10.1109/icee44586.2018.8937953","url":null,"abstract":"In this paper, we introduce an analytical surface potential based model for sheet carrier density and current in N-polar GaN/AlN/AlGaN metal insulator semiconductor high electron mobility transistors (MIS-HEMTs). The proposed sheet carrier density model is derived in terms of Fermi-level $(E_{f})$, gate potential $(V_{g})$ and channel potential $(V_{c})$. The surface potential current model using charge control equations and high field saturation Canali mobility model are in close agreement with simulation and experimental data over a wide range of applied gate biases.","PeriodicalId":6590,"journal":{"name":"2018 4th IEEE International Conference on Emerging Electronics (ICEE)","volume":"3 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77793929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-01DOI: 10.1109/icee44586.2018.8938018
A. Chatterjee, S. K. Khamari, S. Porwal, T. Sharma
GaN metal-semiconductor-metal (MSM)ultraviolet photodetectors without and with annealed ZrO2 insulating layers are successfully fabricated. It is found that the dark current is reduced by 3 times post annealing of the oxide layer. GaN MSM photo detectors exhibit large internal gain which can be explained by considering the presence of hole traps in oxide layer. Further, reduction in gain and increase intransient response time of photodetectors post annealing of ZrO2 layer reveal that the density of shallow trap states is considerably reduced by the annealing step. It is noticed that though the response of all the states is affected by the annealing but the fast component of photo response is rather severely hampered. The present investigations clearly demonstrate that reduction of dark current is not the sole criteria for improving the performance of a photodetector. Rather, transient response of the device and hence the bandwidth of the device along with the leakage current and gain should be taken into consideration for qualifying the overall performance of the photodetectors.
{"title":"Impact of post deposition annealing of ZrO2 insulating layer on the performance of GaN metal-semiconductor-metal ultraviolet photodetectors","authors":"A. Chatterjee, S. K. Khamari, S. Porwal, T. Sharma","doi":"10.1109/icee44586.2018.8938018","DOIUrl":"https://doi.org/10.1109/icee44586.2018.8938018","url":null,"abstract":"GaN metal-semiconductor-metal (MSM)ultraviolet photodetectors without and with annealed ZrO2 insulating layers are successfully fabricated. It is found that the dark current is reduced by 3 times post annealing of the oxide layer. GaN MSM photo detectors exhibit large internal gain which can be explained by considering the presence of hole traps in oxide layer. Further, reduction in gain and increase intransient response time of photodetectors post annealing of ZrO2 layer reveal that the density of shallow trap states is considerably reduced by the annealing step. It is noticed that though the response of all the states is affected by the annealing but the fast component of photo response is rather severely hampered. The present investigations clearly demonstrate that reduction of dark current is not the sole criteria for improving the performance of a photodetector. Rather, transient response of the device and hence the bandwidth of the device along with the leakage current and gain should be taken into consideration for qualifying the overall performance of the photodetectors.","PeriodicalId":6590,"journal":{"name":"2018 4th IEEE International Conference on Emerging Electronics (ICEE)","volume":"15 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81569912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-01DOI: 10.1109/icee44586.2018.8937977
M. Angappan, Pritom J. Bora, M. Hs, Vinoy Kj, Kishore, Praveen C Ramamurthy, K. Vijayaraju
In search of novel light weight broadband microwave absorber for defense and civilian applications, industrial waste hollow microsphere (fly ash cenosphere or FAC) filler based polymer composite system was studied in the present work owing to its attractive microwave absorbing characteristics. PDMS is chosen as the matrix. FAC, being dielectric, is coated with Ni using standard electroless coating method to synthesize core-shell filler (magneto-dielectric). The dielectrics and microwave absorption study was carried out for the frequency range 8.2-18 GHz (X-band and Ku-Band). The minimum reflection loss (RL) was obtained to be -43 dB with an excellent bandwidth. Hence, an ultra-thin Ni coated FAC loaded PDMS can be considered as a smart candidate for broad band microwave absorption.
{"title":"PDMS-Ni coated flyash cenosphere composite for broadband microwave absorption","authors":"M. Angappan, Pritom J. Bora, M. Hs, Vinoy Kj, Kishore, Praveen C Ramamurthy, K. Vijayaraju","doi":"10.1109/icee44586.2018.8937977","DOIUrl":"https://doi.org/10.1109/icee44586.2018.8937977","url":null,"abstract":"In search of novel light weight broadband microwave absorber for defense and civilian applications, industrial waste hollow microsphere (fly ash cenosphere or FAC) filler based polymer composite system was studied in the present work owing to its attractive microwave absorbing characteristics. PDMS is chosen as the matrix. FAC, being dielectric, is coated with Ni using standard electroless coating method to synthesize core-shell filler (magneto-dielectric). The dielectrics and microwave absorption study was carried out for the frequency range 8.2-18 GHz (X-band and Ku-Band). The minimum reflection loss (RL) was obtained to be -43 dB with an excellent bandwidth. Hence, an ultra-thin Ni coated FAC loaded PDMS can be considered as a smart candidate for broad band microwave absorption.","PeriodicalId":6590,"journal":{"name":"2018 4th IEEE International Conference on Emerging Electronics (ICEE)","volume":"2008 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82571371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-01DOI: 10.1109/icee44586.2018.8937860
Rinky Sha, L. Durai, Sushmee Badhulika
This paper reports a novel and low cost hydrothermal method for the in-situ preparation of few-layered reduced graphene oxide – niobium pentoxide composite for non-enzymatic detection of glucose. TEM, XRD and Raman spectroscopic results confirmed the successful growth of few-layered two dimensional reduced graphene oxide – spherical niobium-pentoxide nanoparticles based (rGO-Nb2 O5) composite. The as-fabricated rGO-Nb2 O5 sensor exhibited a sensitivity of $3.23 mumathrm{A}$. mM-1 with an excellent linearity (R2=0.994) in the physiological range of blood glucose (1-10 mM). The sensing ability of the composite based sensor towards glucose was explained in terms of forward biased nano Schottky barriers at the rGO-Nb2 O5 interface. This work further can be extended for the non-enzymatic detection of glucose in saliva, tears or urine samples.
{"title":"Facile in-situ preparation of few-layered reduced graphene oxide – niobium pentoxide composite for non-enzymatic glucose monitoring","authors":"Rinky Sha, L. Durai, Sushmee Badhulika","doi":"10.1109/icee44586.2018.8937860","DOIUrl":"https://doi.org/10.1109/icee44586.2018.8937860","url":null,"abstract":"This paper reports a novel and low cost hydrothermal method for the in-situ preparation of few-layered reduced graphene oxide – niobium pentoxide composite for non-enzymatic detection of glucose. TEM, XRD and Raman spectroscopic results confirmed the successful growth of few-layered two dimensional reduced graphene oxide – spherical niobium-pentoxide nanoparticles based (rGO-Nb2 O5) composite. The as-fabricated rGO-Nb2 O5 sensor exhibited a sensitivity of $3.23 mumathrm{A}$. mM-1 with an excellent linearity (R2=0.994) in the physiological range of blood glucose (1-10 mM). The sensing ability of the composite based sensor towards glucose was explained in terms of forward biased nano Schottky barriers at the rGO-Nb2 O5 interface. This work further can be extended for the non-enzymatic detection of glucose in saliva, tears or urine samples.","PeriodicalId":6590,"journal":{"name":"2018 4th IEEE International Conference on Emerging Electronics (ICEE)","volume":"100 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83738856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-01DOI: 10.1109/icee44586.2018.8938003
Krutikesh Sahoo, P. Sen, N. Bhat
In this paper we propose a two-terminal diode type nano-electro-mechanical (NEM) switch with a low actuation voltage of about 2.5 V and sharp subthreshold slope of $sim 2.4$ mV/decade obtained by reducing the air gap between electrodes. This type of switch will find applications in non-volatile memory, NEM resonators and sensors.
{"title":"Low Actuation Voltage Nano-Electro-Mechanical Switching Device for Ultra-Low Power Applications","authors":"Krutikesh Sahoo, P. Sen, N. Bhat","doi":"10.1109/icee44586.2018.8938003","DOIUrl":"https://doi.org/10.1109/icee44586.2018.8938003","url":null,"abstract":"In this paper we propose a two-terminal diode type nano-electro-mechanical (NEM) switch with a low actuation voltage of about 2.5 V and sharp subthreshold slope of $sim 2.4$ mV/decade obtained by reducing the air gap between electrodes. This type of switch will find applications in non-volatile memory, NEM resonators and sensors.","PeriodicalId":6590,"journal":{"name":"2018 4th IEEE International Conference on Emerging Electronics (ICEE)","volume":"10 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84019434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-01DOI: 10.1109/icee44586.2018.8938000
Dibakar Yadav, D. Nair
Materials with a light effective mass and high mobility are known to provide better performance for long channel transistors. However, with transistor dimensions scaling to sub-10 nm lengths, source to drain tunneling (SDT) becomes a major performance limiting factor for high mobility materials. In this paper, we examine the effect of SDT on the performance of germanium-tin (GeSn) short channel Nanowire (NW) p-MOSEFTs using rigorous ballistic quantum transport simulations. We simulate GeSn NWs in different transport orientations and with Sn mole fraction values of 0.05 and 0.11 to identify the channel direction with optimum effective mass to limit SDT. We also examine the role of reduced source/drain doping in enhancing the on-state performance of GeSn NWs by limiting SDT current in off-state.
{"title":"Performance Evaluation of Germanium-Tin Nanowire PFETs: Impact of Mole Fraction, Orientation and Doping","authors":"Dibakar Yadav, D. Nair","doi":"10.1109/icee44586.2018.8938000","DOIUrl":"https://doi.org/10.1109/icee44586.2018.8938000","url":null,"abstract":"Materials with a light effective mass and high mobility are known to provide better performance for long channel transistors. However, with transistor dimensions scaling to sub-10 nm lengths, source to drain tunneling (SDT) becomes a major performance limiting factor for high mobility materials. In this paper, we examine the effect of SDT on the performance of germanium-tin (GeSn) short channel Nanowire (NW) p-MOSEFTs using rigorous ballistic quantum transport simulations. We simulate GeSn NWs in different transport orientations and with Sn mole fraction values of 0.05 and 0.11 to identify the channel direction with optimum effective mass to limit SDT. We also examine the role of reduced source/drain doping in enhancing the on-state performance of GeSn NWs by limiting SDT current in off-state.","PeriodicalId":6590,"journal":{"name":"2018 4th IEEE International Conference on Emerging Electronics (ICEE)","volume":"26 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79019989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-01DOI: 10.1109/icee44586.2018.8937959
M. Garg, B. R. Tak, V. Rao, Rajendra Singh
Organic molecular monolayers have been used for improving the performance of various electronic device structures. In this work, the concept of organic molecular surface modification is applied for improving the performance and the self-power quality of GaN-based symmetric Metal-Semiconductor-Metal (MSM) Ultraviolet (UV) Photodetectors (PDs). Organic molecules of phenol-functionalized-metallated Porphyrin (Zn-TPPOH) have been adsorbed on GaN epitaxial layers and Ni/Zn-TPPOH/GaN/Zn-TPPOH/Ni PD structures have been fabricated. This process has led to decrease in reverse bias dark current by $sim10,000 times$ at 0V in comparison to the dark current values obtained for Ni/GaN/Ni MSM PDs. Photodetector parameters such as Photo-to-dark current ratio and Responsivity have increased from 8.8 and 0.004 A/W for Ni/GaN/Ni structures to $2.4 times10^{5}$ and 0.038 A/W for Ni/Zn-TPPOH/GaN/Zn-TPPOH/Ni structures, respectively at 0V. The spectral selectivity of the PDs has also improved at 0V, which means that the molecularly modified devices have become more responsive in UV spectral region and lesser in visible spectral region, if compared to bare-GaN based devices.
{"title":"Improvement in Self-Powered GaN-based Symmetric Metal-Semiconductor-Metal Ultraviolet Photodetectors by Using Phenol-Functionalized Porphyrin Organic Molecules","authors":"M. Garg, B. R. Tak, V. Rao, Rajendra Singh","doi":"10.1109/icee44586.2018.8937959","DOIUrl":"https://doi.org/10.1109/icee44586.2018.8937959","url":null,"abstract":"Organic molecular monolayers have been used for improving the performance of various electronic device structures. In this work, the concept of organic molecular surface modification is applied for improving the performance and the self-power quality of GaN-based symmetric Metal-Semiconductor-Metal (MSM) Ultraviolet (UV) Photodetectors (PDs). Organic molecules of phenol-functionalized-metallated Porphyrin (Zn-TPPOH) have been adsorbed on GaN epitaxial layers and Ni/Zn-TPPOH/GaN/Zn-TPPOH/Ni PD structures have been fabricated. This process has led to decrease in reverse bias dark current by $sim10,000 times$ at 0V in comparison to the dark current values obtained for Ni/GaN/Ni MSM PDs. Photodetector parameters such as Photo-to-dark current ratio and Responsivity have increased from 8.8 and 0.004 A/W for Ni/GaN/Ni structures to $2.4 times10^{5}$ and 0.038 A/W for Ni/Zn-TPPOH/GaN/Zn-TPPOH/Ni structures, respectively at 0V. The spectral selectivity of the PDs has also improved at 0V, which means that the molecularly modified devices have become more responsive in UV spectral region and lesser in visible spectral region, if compared to bare-GaN based devices.","PeriodicalId":6590,"journal":{"name":"2018 4th IEEE International Conference on Emerging Electronics (ICEE)","volume":"7 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89594583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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