Flat panel displays (FPD), flexible electronics and thin-film photovoltaics are booming in the last few years. Permanent annual growth and huge expectations in the market in the near future stimulate the development of versatile technologies for patterning thin-film materials on rigid and flexible substrates. Utilization of laser radiation provides diversity of processing means for structuring deposited films. The high selectivity and diminishing effect on the surrounding material as well as high speed are required in processing complex multilayered systems in the thin-film photovoltaics. Organic electronics imposes special requirements on the geometrical quality of conductors. The current situation with laser direct writing of thin-films in the production of FPD and solar cells as well as our results are presented. High repetition rate lasers with a short pulse duration offer new possibilities for high efficiency structuring of conducting, semi-conducting and isolating films. Laser structuring with the picosecond and nanosecond pulse duration was applied in shaping the thin films deposited on polymers and glass substrates. Absorption of laser radiation by the film material was essential to initiate its controllable removal. Use of UV laser radiation with fluences close to the ablation threshold made it possible to minimize surface contamination and the recast ridge formation during the ablation process. The flexible technique of patterning was applied in prototyping the components for the OLED matrix, RFID antennas and the thin-film solar cells. Well-defined shapes of isolating trenches and conductor lines were produced by laser ablation with the picosecond pulse duration.
{"title":"Laser structuring of conducting films on transparent substrates for electronics devices","authors":"G. Račiukaitis","doi":"10.1117/12.815322","DOIUrl":"https://doi.org/10.1117/12.815322","url":null,"abstract":"Flat panel displays (FPD), flexible electronics and thin-film photovoltaics are booming in the last few years. Permanent annual growth and huge expectations in the market in the near future stimulate the development of versatile technologies for patterning thin-film materials on rigid and flexible substrates. Utilization of laser radiation provides diversity of processing means for structuring deposited films. The high selectivity and diminishing effect on the surrounding material as well as high speed are required in processing complex multilayered systems in the thin-film photovoltaics. Organic electronics imposes special requirements on the geometrical quality of conductors. The current situation with laser direct writing of thin-films in the production of FPD and solar cells as well as our results are presented. High repetition rate lasers with a short pulse duration offer new possibilities for high efficiency structuring of conducting, semi-conducting and isolating films. Laser structuring with the picosecond and nanosecond pulse duration was applied in shaping the thin films deposited on polymers and glass substrates. Absorption of laser radiation by the film material was essential to initiate its controllable removal. Use of UV laser radiation with fluences close to the ablation threshold made it possible to minimize surface contamination and the recast ridge formation during the ablation process. The flexible technique of patterning was applied in prototyping the components for the OLED matrix, RFID antennas and the thin-film solar cells. Well-defined shapes of isolating trenches and conductor lines were produced by laser ablation with the picosecond pulse duration.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"1 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121794074","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}
Z. Dashevsky, V. Kasiyan, G. Radovsky, E. Shufer, M. Auslender
Lead salt materials are of high interest for midinfrared optical emitters and detectors for molecular spectroscopy. The IV-VI narrow gap semiconductors have a multivalley band structure with band extrema at the L point of the Brillioun zone. Due to the favorable mirrorlike band structure, the nonradiative Auger recombination is reduced by one or two orders of magnitude below that of narrow gap III-V and II-VI semiconductor compounds1. The photoluminescence in the midinfrared range for PbSe film structures, excited by a semiconductor laser diode, is investigated. The PbSe films were prepared by Physical Vapor Deposition (PVD) using an electron gun. A PbSe crystal doped with 0.1 at% Bi was used as a source for the fabrication of thin layers. Starting from the assumption that the rate of nucleation is a predominate factor in determining grain size, thin films were fabricated on substrates that had been maintained at various temperatures of deposition process2. Amorphous glass and Kapton polyimide film was used as substrate. The growth rate was 0.2 nm/s. Films were thermally treated at high oxygen pressure in a heated encapsulated system. Microstructure has been studied using XRD, AFM and HRSEM. For PbSe structures photoluminescence at temperature as high as 300 K is demonstrated.
{"title":"Mid-infrared photoluminescence of PbSe film structures up to room temperature","authors":"Z. Dashevsky, V. Kasiyan, G. Radovsky, E. Shufer, M. Auslender","doi":"10.1117/12.815199","DOIUrl":"https://doi.org/10.1117/12.815199","url":null,"abstract":"Lead salt materials are of high interest for midinfrared optical emitters and detectors for molecular spectroscopy. The IV-VI narrow gap semiconductors have a multivalley band structure with band extrema at the L point of the Brillioun zone. Due to the favorable mirrorlike band structure, the nonradiative Auger recombination is reduced by one or two orders of magnitude below that of narrow gap III-V and II-VI semiconductor compounds1. The photoluminescence in the midinfrared range for PbSe film structures, excited by a semiconductor laser diode, is investigated. The PbSe films were prepared by Physical Vapor Deposition (PVD) using an electron gun. A PbSe crystal doped with 0.1 at% Bi was used as a source for the fabrication of thin layers. Starting from the assumption that the rate of nucleation is a predominate factor in determining grain size, thin films were fabricated on substrates that had been maintained at various temperatures of deposition process2. Amorphous glass and Kapton polyimide film was used as substrate. The growth rate was 0.2 nm/s. Films were thermally treated at high oxygen pressure in a heated encapsulated system. Microstructure has been studied using XRD, AFM and HRSEM. For PbSe structures photoluminescence at temperature as high as 300 K is demonstrated.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127747146","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}
The researches of the possibility of Au nanoparticles formation in conditions of surface plasmon resonance (SPR) at irradiation of the Au film / glass structure by YAG:Nd+3-laser nanosecond pulses of the p-polarization (tp = 10 ns) by fundamental (λ = 1.064 nm) and second harmonics (λ = 0.532 nm) are submitted. The morphology of an Au film surface before and after laser action, Au fragments sizes and their surface distribution were investigated by the atom force microscopy (AFM). The effect of Au nanoparticles formation was observed only at the second harmonic irradiation (λ= 0.532 μm) in SPR conditions in the Kretschmann configuration. The considerable difference between the average Au nanoparticles sizes δ created at the SPR conditions, R = Rmin, δ ~ 80 nm that was obtained in the case out of SPR R≠Rmin δ ~ 1350 nm is established. Threshold energy density of micro-ablation Pthn is determined, that one in the case of SPR Pthn ≈ 5.5 J•cm-2 was essentially lower than in the SPR absence, Pthn ≈ 8 J cm-2. The histogram obtained on the AFM data has shown a high degree of the height sizes homogeneity of Au nanoparticles. Under the AFM data a conclusion about the determining contribution of the plasmon - polariton subsystem in formation process of Au nanoparticles in SPR conditions at high levels of laser irradiation was made.
{"title":"Self-organizing laser induced Au nanocrystall formation in conditions of surface plasmon resonance","authors":"L. Fedorenko, M. Yusupov","doi":"10.1117/12.815449","DOIUrl":"https://doi.org/10.1117/12.815449","url":null,"abstract":"The researches of the possibility of Au nanoparticles formation in conditions of surface plasmon resonance (SPR) at irradiation of the Au film / glass structure by YAG:Nd+3-laser nanosecond pulses of the p-polarization (tp = 10 ns) by fundamental (λ = 1.064 nm) and second harmonics (λ = 0.532 nm) are submitted. The morphology of an Au film surface before and after laser action, Au fragments sizes and their surface distribution were investigated by the atom force microscopy (AFM). The effect of Au nanoparticles formation was observed only at the second harmonic irradiation (λ= 0.532 μm) in SPR conditions in the Kretschmann configuration. The considerable difference between the average Au nanoparticles sizes δ created at the SPR conditions, R = Rmin, δ ~ 80 nm that was obtained in the case out of SPR R≠Rmin δ ~ 1350 nm is established. Threshold energy density of micro-ablation Pthn is determined, that one in the case of SPR Pthn ≈ 5.5 J•cm-2 was essentially lower than in the SPR absence, Pthn ≈ 8 J cm-2. The histogram obtained on the AFM data has shown a high degree of the height sizes homogeneity of Au nanoparticles. Under the AFM data a conclusion about the determining contribution of the plasmon - polariton subsystem in formation process of Au nanoparticles in SPR conditions at high levels of laser irradiation was made.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132839068","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}
A. Bulanovs, V. Gerbreders, Ē. Sļedevskis, V. Pashkevich, J. Teteris
We have performed the investigation of dot matrix holographic recording in amorphous As2S3 chalcogenide films with different thickness on Al coated glass substrates. The control over the interference minimum of reflection during the evaporation process allowed obtaining As2S3-Al system with a minimum value of initial reflection in defined spectral region. The investigation of dependence of diffraction efficiency of holographic recording on both film thickness and initial conditions of reflectivity in the system was performed. The main advantage of this type of system is the possibility to increase optical sensitivity of material in predefined spectrum region for phase hologram recording.
{"title":"Investigation of As2S3-Al films for dot-matrix holographic recording","authors":"A. Bulanovs, V. Gerbreders, Ē. Sļedevskis, V. Pashkevich, J. Teteris","doi":"10.1117/12.815436","DOIUrl":"https://doi.org/10.1117/12.815436","url":null,"abstract":"We have performed the investigation of dot matrix holographic recording in amorphous As2S3 chalcogenide films with different thickness on Al coated glass substrates. The control over the interference minimum of reflection during the evaporation process allowed obtaining As2S3-Al system with a minimum value of initial reflection in defined spectral region. The investigation of dependence of diffraction efficiency of holographic recording on both film thickness and initial conditions of reflectivity in the system was performed. The main advantage of this type of system is the possibility to increase optical sensitivity of material in predefined spectrum region for phase hologram recording.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134086563","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}
We report the experimental data of typical liquid crystals (6CHBT and w1680) in the nematic phase doped with and without Sudan dyes. We investigated the effect of an ac-applied voltage on the nonlinear behavior of dye doped liquid crystal (DDLC). The z-scan technique is used to measure the amplitude and the sign of the nonlinear refractive indices DDLC. The amplitude of negative nonlinear refractive indices was (~10-5cm2/W). The nonlinear absorption coefficient β of DDLC was measured by using open aperture z- scan technique. Also the optical limiting (OL) response of DDLC was obtained. The novel effects on the far-field diffraction patterns of a Gaussian beam were depended on the external applied field. The measurements were performed using a CW He:Ne laser and CW Nd:Yag laser tuned at 632.8 nm and 532 nm, respectively. Also Gaussian beam propagated through a thin cell (sample thickness =11.8 μm).
{"title":"The effects of external applied voltage on the nonlinear optical properties of a dye-doped nematic liquid crystal by using a single beam","authors":"M. H. Majles Ara, R. Bahramian, M. Abolhasani","doi":"10.1117/12.815901","DOIUrl":"https://doi.org/10.1117/12.815901","url":null,"abstract":"We report the experimental data of typical liquid crystals (6CHBT and w1680) in the nematic phase doped with and without Sudan dyes. We investigated the effect of an ac-applied voltage on the nonlinear behavior of dye doped liquid crystal (DDLC). The z-scan technique is used to measure the amplitude and the sign of the nonlinear refractive indices DDLC. The amplitude of negative nonlinear refractive indices was (~10-5cm2/W). The nonlinear absorption coefficient β of DDLC was measured by using open aperture z- scan technique. Also the optical limiting (OL) response of DDLC was obtained. The novel effects on the far-field diffraction patterns of a Gaussian beam were depended on the external applied field. The measurements were performed using a CW He:Ne laser and CW Nd:Yag laser tuned at 632.8 nm and 532 nm, respectively. Also Gaussian beam propagated through a thin cell (sample thickness =11.8 μm).","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122740510","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}
The quaternary alloy InxGa1-xAsySb1-y highly doped with tellurium was grown on substrates of p-type GaSb in the direction (100) by liquid phase epitaxy (LPE). The longitudinal (LO) and transverse (TO) optical modes were obtained using the modified random-element iso-displacement model (MREI model). The comparison of the experimental results with obtained by the MREI model allows to confirm that the bands correspond to the modes associated LO and TO of the binary compounds GaAs and (GaSb + InAs).
{"title":"Lattice vibrations study of InxGa1-xAsySb1-y quaternary alloys with low (In, As) content highly doped by tellurium grown by LPE","authors":"J. Díaz-Reyes, E. López-Cruz, J. Mendoza-Álvarez","doi":"10.1117/12.815961","DOIUrl":"https://doi.org/10.1117/12.815961","url":null,"abstract":"The quaternary alloy InxGa1-xAsySb1-y highly doped with tellurium was grown on substrates of p-type GaSb in the direction (100) by liquid phase epitaxy (LPE). The longitudinal (LO) and transverse (TO) optical modes were obtained using the modified random-element iso-displacement model (MREI model). The comparison of the experimental results with obtained by the MREI model allows to confirm that the bands correspond to the modes associated LO and TO of the binary compounds GaAs and (GaSb + InAs).","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121159513","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}
M. Polakovs, Ņ. Mironova-Ulmane, N. Kurjāne, E. Reinholds, M. Grube
Confocal micro-Raman and FT-IR spectroscopies have been used for detection of radiation influence of hemoglobin of patients examined by radio-isotopes diagnosis (Tc99m). After irradiation we observed some little changes of the Raman scattering bands which connected with out of plane porphyrine bending vibrations, also we observed additional band due to methemoglobin. Radiation of blood lead to the transition from hemoglobin (Fe2+) to methemoglobin (Fe3+) with a delocalization of iron from porphyrine plane. It was shown that FT-IR spectra indicate the radiation effects on hemoglobin.
{"title":"Micro-Raman scattering and infrared spectra of hemoglobin","authors":"M. Polakovs, Ņ. Mironova-Ulmane, N. Kurjāne, E. Reinholds, M. Grube","doi":"10.1117/12.815796","DOIUrl":"https://doi.org/10.1117/12.815796","url":null,"abstract":"Confocal micro-Raman and FT-IR spectroscopies have been used for detection of radiation influence of hemoglobin of patients examined by radio-isotopes diagnosis (Tc99m). After irradiation we observed some little changes of the Raman scattering bands which connected with out of plane porphyrine bending vibrations, also we observed additional band due to methemoglobin. Radiation of blood lead to the transition from hemoglobin (Fe2+) to methemoglobin (Fe3+) with a delocalization of iron from porphyrine plane. It was shown that FT-IR spectra indicate the radiation effects on hemoglobin.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122871261","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}
Thin films of tungsten oxide (WO3) have been grown by hot-filament metal oxide deposition (HFMOD) technique under atmospheric pressure and an oxygen atmosphere on glass substrates. The thin film of WO3 has been extensively studied as an electrochromic material and has numerous applications in electrochromic devices. In order to explore the possibility of using WO3 in electrochromic devices, a preliminary and thorough study of the structural and optical properties of the host material is an important step. By the X-ray diffraction analysis the single phase natures, monoclinic and orthorhombic structure of the films have been confirmed. The IR spectra were constituted of many broad peaks in the 1400-3500 cm-1 region That are assigned to ν(OH) and δ(OH) modes of adsorbed water. The corresponding WO3 vibrations are in infrared regions of 1453-400 cm-1 and 3454 cm-1, which correspond to W-O stretching, bending and lattice modes. By Transmittance measures determines that the optical bandgap is around 2.92 eV. We have observed that the good quality WO3 thin films can be satisfactorily grown by this technique.
{"title":"A method for deposition of tungsten trioxide (WO3)","authors":"J. Martínez-Juárez, J. Díaz-Reyes","doi":"10.1117/12.815958","DOIUrl":"https://doi.org/10.1117/12.815958","url":null,"abstract":"Thin films of tungsten oxide (WO3) have been grown by hot-filament metal oxide deposition (HFMOD) technique under atmospheric pressure and an oxygen atmosphere on glass substrates. The thin film of WO3 has been extensively studied as an electrochromic material and has numerous applications in electrochromic devices. In order to explore the possibility of using WO3 in electrochromic devices, a preliminary and thorough study of the structural and optical properties of the host material is an important step. By the X-ray diffraction analysis the single phase natures, monoclinic and orthorhombic structure of the films have been confirmed. The IR spectra were constituted of many broad peaks in the 1400-3500 cm-1 region That are assigned to ν(OH) and δ(OH) modes of adsorbed water. The corresponding WO3 vibrations are in infrared regions of 1453-400 cm-1 and 3454 cm-1, which correspond to W-O stretching, bending and lattice modes. By Transmittance measures determines that the optical bandgap is around 2.92 eV. We have observed that the good quality WO3 thin films can be satisfactorily grown by this technique.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"35 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134033596","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}
A. Kadys, K. Jarašiūnas, P. Delaye, D. Verstraeten
We demonstrate a novel application of time-resolved transient grating technique for determination of deep trap occupation ratio in semi-insulating crystals. Light diffraction kinetics on a transient reflection grating with very small period (150 nm) provided conditions for studies of absorption nonlinearity and its discrimination from the coexisting free carrier and electro-optic ones. By numerical modeling of absorption grating kinetics in subnanosecond time domain, we determined the contributions of the recharged deep traps and two-photon absorption to diffraction kinetics and evaluated in this way the deep trap compensation ratio in differently grown GaAs crystals. Moreover, the decay time of the absorption grating provided the rate of carrier capture to these dominant deep traps, which have been recharged under illumination. Using this feature, we were able to monitor the thermal annealing process in vanadium-doped CdTe crystals: it has not effected the charge state of vanadium related deep traps, but reduced the concentration of the active residual carrier capture centers in the crystal.
{"title":"Evaluation of deep trap compensation ratio and recombination parameters by transient grating techniques","authors":"A. Kadys, K. Jarašiūnas, P. Delaye, D. Verstraeten","doi":"10.1117/12.815623","DOIUrl":"https://doi.org/10.1117/12.815623","url":null,"abstract":"We demonstrate a novel application of time-resolved transient grating technique for determination of deep trap occupation ratio in semi-insulating crystals. Light diffraction kinetics on a transient reflection grating with very small period (150 nm) provided conditions for studies of absorption nonlinearity and its discrimination from the coexisting free carrier and electro-optic ones. By numerical modeling of absorption grating kinetics in subnanosecond time domain, we determined the contributions of the recharged deep traps and two-photon absorption to diffraction kinetics and evaluated in this way the deep trap compensation ratio in differently grown GaAs crystals. Moreover, the decay time of the absorption grating provided the rate of carrier capture to these dominant deep traps, which have been recharged under illumination. Using this feature, we were able to monitor the thermal annealing process in vanadium-doped CdTe crystals: it has not effected the charge state of vanadium related deep traps, but reduced the concentration of the active residual carrier capture centers in the crystal.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133997211","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}
J. Matukas, V. Palenskis, J. Vyšniauskas, B. Saulys, S. Pralgauskaitė, A. Pincevičius
High power white light emission diode reliability and aging processes have been investigated. Optical, electrical and noise characteristics have been carried out for initial devices and during their aging. Analysis of noise characteristics help revealing of light emission diode aging processes and reliability problems. It is found that optical and electrical noise spectra changes reflect light emission diode aging. Noise characteristics, especially correlation factor between optical and electrical fluctuations, and current-voltage characteristics at low bias reveal physical processes that take place during investigated device aging and rapid its degradation. It is shown that reason of high power light emission diode degradation is related with defects presence in the device structure. Additional defects appear during LED operation and lead to the leakage current and non-radiative recombination increase.
{"title":"Noise characteristics and reliability of high power white light emitting diodes based on nitrides","authors":"J. Matukas, V. Palenskis, J. Vyšniauskas, B. Saulys, S. Pralgauskaitė, A. Pincevičius","doi":"10.1117/12.816513","DOIUrl":"https://doi.org/10.1117/12.816513","url":null,"abstract":"High power white light emission diode reliability and aging processes have been investigated. Optical, electrical and noise characteristics have been carried out for initial devices and during their aging. Analysis of noise characteristics help revealing of light emission diode aging processes and reliability problems. It is found that optical and electrical noise spectra changes reflect light emission diode aging. Noise characteristics, especially correlation factor between optical and electrical fluctuations, and current-voltage characteristics at low bias reveal physical processes that take place during investigated device aging and rapid its degradation. It is shown that reason of high power light emission diode degradation is related with defects presence in the device structure. Additional defects appear during LED operation and lead to the leakage current and non-radiative recombination increase.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"7142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129442275","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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