S. Nargelas, R. Aleksieju̅nas, A. Kadys, V. Gudelis, K. Jarašiūnas
Time-integrated and time-resolved FWM techniques were applied for characterization of the photoelectrical properties of undoped, S-doped, and Fe-doped InP wafers and for a mapping of their homogeneity. We performed measurements of spatial distribution of diffraction efficiency across the wafers by nanosecond FWM and investigated a physical origin of the observed variations by using time-resolved picosecond FWM. By analyzing the diffraction efficiency kinetics and its dependence on excitation energy, we evaluated the impurity-assisted carrier generation, recombination, diffusion processes, electrical activity of the defects, and their distribution across the wafers. Carrier lifetime variation from 2.5 ns to 7.5 ns across the undoped InP wafer was found, while the diffusion coefficient value of 8 ± 0.5 cm2/s was almost constant. In S-doped InP wafer, wafer inhomogeneity was attributed to carrier generation peculiarities governed by spatial distribution of deep centers.
{"title":"Mapping of differently doped InP wafers by nanosecond and picosecond four-wave mixing techniques","authors":"S. Nargelas, R. Aleksieju̅nas, A. Kadys, V. Gudelis, K. Jarašiūnas","doi":"10.1117/12.726447","DOIUrl":"https://doi.org/10.1117/12.726447","url":null,"abstract":"Time-integrated and time-resolved FWM techniques were applied for characterization of the photoelectrical properties of undoped, S-doped, and Fe-doped InP wafers and for a mapping of their homogeneity. We performed measurements of spatial distribution of diffraction efficiency across the wafers by nanosecond FWM and investigated a physical origin of the observed variations by using time-resolved picosecond FWM. By analyzing the diffraction efficiency kinetics and its dependence on excitation energy, we evaluated the impurity-assisted carrier generation, recombination, diffusion processes, electrical activity of the defects, and their distribution across the wafers. Carrier lifetime variation from 2.5 ns to 7.5 ns across the undoped InP wafer was found, while the diffusion coefficient value of 8 ± 0.5 cm2/s was almost constant. In S-doped InP wafer, wafer inhomogeneity was attributed to carrier generation peculiarities governed by spatial distribution of deep centers.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124417533","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. Martūnas, D. Seliuta, I. Kašalynas, V. Tamošiūnas, G. Valušis
New approach to measure a magnetic component of a microwave radiation via sub-harmonic mixing in high-Tc superconductor Bi2Sr2CaCu2O8 layer kept close to the transition temperature Tc is suggested. Employing an electrical nonlinearity near the transition, we have mixed alternating electrical field of 1 MHz and 2 MHz frequencies in the sample placed on the narrow wall of the waveguide for 10 GHz frequency range. The recording principle is illustrated showing the relation between the amplitude of the mixing signal and the microwave magnetic field component in a standing wave experiment. The underlining idea is also confirmed by experimental data obtained measuring the third order nonlinearity recorded by the application of the double-modulation approach in the microwave range.
{"title":"Measurement of the magnetic component of microwave electromagnetic radiation via sub-harmonic mixing","authors":"Z. Martūnas, D. Seliuta, I. Kašalynas, V. Tamošiūnas, G. Valušis","doi":"10.1117/12.726401","DOIUrl":"https://doi.org/10.1117/12.726401","url":null,"abstract":"New approach to measure a magnetic component of a microwave radiation via sub-harmonic mixing in high-Tc superconductor Bi2Sr2CaCu2O8 layer kept close to the transition temperature Tc is suggested. Employing an electrical nonlinearity near the transition, we have mixed alternating electrical field of 1 MHz and 2 MHz frequencies in the sample placed on the narrow wall of the waveguide for 10 GHz frequency range. The recording principle is illustrated showing the relation between the amplitude of the mixing signal and the microwave magnetic field component in a standing wave experiment. The underlining idea is also confirmed by experimental data obtained measuring the third order nonlinearity recorded by the application of the double-modulation approach in the microwave range.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121933216","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}
Evgeny N. Kotlikov, Boris N. Gumenik, V. A. Ivanov, Elena V. Khonineva, Vadim N. Prokashev, M. N. Tkachuk, A. N. Tropin
Interference coating for infrared spectral region required the transparent optical films with different refraction indexes and minimal an absorption factor. It is well known1, that chalcogenide materials based on sulphide and selenide are the perspective film's forming materials for manufacturing of the interference coating (IC). Among the known materials, the minimal absorption factors have arsenic chalcogenide films. The value of optical losses due to absorption and scattering of the quote wave films of As2Se3 on 10 microns wavelength is less than 10-5. It allows using them for manufacturing of the high quality optics in wide optical region, including optics for CO2 powerful lasers1. Despite of good operational characteristics and the small optical losses, many of known chalcogenide materials have not received a wide distribution. One of the reasons of that is the absence of the data of their film's optical constants (OC) of these substances, which strongly depend on a way and conditions of manufacturing and are different from OC of initial monocrystals. In the present work was investigated the optical constants of the chalcogenide films (As2Se3, AsS4, AsSe4, AsS16.2 Se16.2) in 0.5-2.5 (micron)m spectral range.
{"title":"Film's forming materials for laser optics","authors":"Evgeny N. Kotlikov, Boris N. Gumenik, V. A. Ivanov, Elena V. Khonineva, Vadim N. Prokashev, M. N. Tkachuk, A. N. Tropin","doi":"10.1117/12.726519","DOIUrl":"https://doi.org/10.1117/12.726519","url":null,"abstract":"Interference coating for infrared spectral region required the transparent optical films with different refraction indexes and minimal an absorption factor. It is well known1, that chalcogenide materials based on sulphide and selenide are the perspective film's forming materials for manufacturing of the interference coating (IC). Among the known materials, the minimal absorption factors have arsenic chalcogenide films. The value of optical losses due to absorption and scattering of the quote wave films of As2Se3 on 10 microns wavelength is less than 10-5. It allows using them for manufacturing of the high quality optics in wide optical region, including optics for CO2 powerful lasers1. Despite of good operational characteristics and the small optical losses, many of known chalcogenide materials have not received a wide distribution. One of the reasons of that is the absence of the data of their film's optical constants (OC) of these substances, which strongly depend on a way and conditions of manufacturing and are different from OC of initial monocrystals. In the present work was investigated the optical constants of the chalcogenide films (As2Se3, AsS4, AsSe4, AsS16.2 Se16.2) in 0.5-2.5 (micron)m spectral range.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129870951","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}
I. Prosycevas, Algimantas Juraitis, J. Puišo, G. Niaura, A. Guobienė, S. Tamulevičius, G. Balčaitis, A. Šileikaitė
Silver nanoparticles have received considerable attention due to their attractive physical and chemical properties. The surface plasmon resonance and large effective scattering cross section of individual silver nanoparticles make them ideal candidates for molecular labeling, where phenomena such as surface enhance Raman scattering (SERS) can be exploited. In addition, silver nanoparticles have recently been shown to be a promising antimicrobial material. In the present research silver colloid was produced by sodium citrate reduction. The colloidal silver was incorporated by dip-coating to the polymer substrate. X-Ray Fluorescence Spectroscopy (XRF), Atomic force microscopy (AFM), ultraviolet-visible spectroscopy (UV-VIS ) and SERS indicate that the produced structures include metallic crystalline silver nanoparticles. The surface plasmon resonance peak in absorption spectra of silver particles showed an absorption maximum at 420-500 nm. The silver - polymer nanocomposites structures with selective light properties as a result of plasmon resonance shifting in the UV-VIS wavelength region were produced.
{"title":"Synthesis and characterization of silver nanoparticles","authors":"I. Prosycevas, Algimantas Juraitis, J. Puišo, G. Niaura, A. Guobienė, S. Tamulevičius, G. Balčaitis, A. Šileikaitė","doi":"10.1117/12.726403","DOIUrl":"https://doi.org/10.1117/12.726403","url":null,"abstract":"Silver nanoparticles have received considerable attention due to their attractive physical and chemical properties. The surface plasmon resonance and large effective scattering cross section of individual silver nanoparticles make them ideal candidates for molecular labeling, where phenomena such as surface enhance Raman scattering (SERS) can be exploited. In addition, silver nanoparticles have recently been shown to be a promising antimicrobial material. In the present research silver colloid was produced by sodium citrate reduction. The colloidal silver was incorporated by dip-coating to the polymer substrate. X-Ray Fluorescence Spectroscopy (XRF), Atomic force microscopy (AFM), ultraviolet-visible spectroscopy (UV-VIS ) and SERS indicate that the produced structures include metallic crystalline silver nanoparticles. The surface plasmon resonance peak in absorption spectra of silver particles showed an absorption maximum at 420-500 nm. The silver - polymer nanocomposites structures with selective light properties as a result of plasmon resonance shifting in the UV-VIS wavelength region were produced.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133396663","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}
V. Kažukauskas, R. Jasiulionis, V. Kalendra, J. Vaitkus
We had investigated effects of the high-energy proton irradiation on the properties of radiation detectors fabricated as Schottky diodes on 4H-SiC. The doses of 24 GeV protons ranged from 1013 cm-2 up to 1016 cm-2. Numbers and activities of radionuclides and isotopes produced after the irradiation were analysed. Activities of 7Be and 22Na were found to be proportional to the irradiation dose and ranged from 1.3 up to 890 Bq and from 1.9 up to 950 Bq, respectively. The contact properties were investigated by means of the current-voltage analysis. At lower irradiation doses a slight decrease of the effective potential barrier height from about 0.75 eV down to < 0.7 eV took place. The reverse current of the diodes grew by up to one order of magnitude. At the doses above 3x1015 cm-2 opposite changes were observed. Irradiation by up to 1x1016 protons/cm-2, resulted in the increase of the potential barrier height up to ~ 0.85 eV, followed by the drop of the reverse current by up to two orders of magnitude. The observed effects were explained by the appearance of the disordered material structure because of the high-energy particle bombardment.
{"title":"Variation of the properties of 4H-SiC radiation detectors upon irradiation by 24 GeV protons","authors":"V. Kažukauskas, R. Jasiulionis, V. Kalendra, J. Vaitkus","doi":"10.1117/12.726366","DOIUrl":"https://doi.org/10.1117/12.726366","url":null,"abstract":"We had investigated effects of the high-energy proton irradiation on the properties of radiation detectors fabricated as Schottky diodes on 4H-SiC. The doses of 24 GeV protons ranged from 1013 cm-2 up to 1016 cm-2. Numbers and activities of radionuclides and isotopes produced after the irradiation were analysed. Activities of 7Be and 22Na were found to be proportional to the irradiation dose and ranged from 1.3 up to 890 Bq and from 1.9 up to 950 Bq, respectively. The contact properties were investigated by means of the current-voltage analysis. At lower irradiation doses a slight decrease of the effective potential barrier height from about 0.75 eV down to < 0.7 eV took place. The reverse current of the diodes grew by up to one order of magnitude. At the doses above 3x1015 cm-2 opposite changes were observed. Irradiation by up to 1x1016 protons/cm-2, resulted in the increase of the potential barrier height up to ~ 0.85 eV, followed by the drop of the reverse current by up to two orders of magnitude. The observed effects were explained by the appearance of the disordered material structure because of the high-energy particle bombardment.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126968807","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. Medvid, L. Fedorenko, Dmytro V. Korbutjak, S. Kryluk, M. Yusupov, Aleksandr Mychko
A mechanism of formation of graded band-gap based on Thermogradient Effect (TGE) is proposed in Cd1-xZnxTe at irradiation by second harmonic of a Q-switched YAG:Nd laser. According to the effect, the interstitial atoms of Cd (Cdi) in Cd1-xZnxTe move along the temperature gradient while the Cd vacancies (VCd) and Zn atoms - in the opposite direction, into the bulk of the semiconductor where temperature is lower. Photoluminescence (PL) spectra studied at 5 K show that concentration of Zn atoms increases due to aggregation of VCd with Zn after laser irradiation. Formation of a graded band-gap in Cd1-xZnxTe crystal at irradiation by second harmonica of YAG:Nd laser by is shown to be possible.
{"title":"Modification of band gap in surface layer in Cd1-xZnxTe by YAG:Nd+3 laser radiation","authors":"A. Medvid, L. Fedorenko, Dmytro V. Korbutjak, S. Kryluk, M. Yusupov, Aleksandr Mychko","doi":"10.1117/12.726500","DOIUrl":"https://doi.org/10.1117/12.726500","url":null,"abstract":"A mechanism of formation of graded band-gap based on Thermogradient Effect (TGE) is proposed in Cd1-xZnxTe at irradiation by second harmonic of a Q-switched YAG:Nd laser. According to the effect, the interstitial atoms of Cd (Cdi) in Cd1-xZnxTe move along the temperature gradient while the Cd vacancies (VCd) and Zn atoms - in the opposite direction, into the bulk of the semiconductor where temperature is lower. Photoluminescence (PL) spectra studied at 5 K show that concentration of Zn atoms increases due to aggregation of VCd with Zn after laser irradiation. Formation of a graded band-gap in Cd1-xZnxTe crystal at irradiation by second harmonica of YAG:Nd laser by is shown to be possible.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126740672","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, Vjacheslavs Gerbreders, Valfrids Paschkevich, J. Teteris
We have developed PC controlled dot-matrix holographic recording system based on the CW diode pumped YAG:Nd SHG laser (wavelength 532 nm, power 30mW,) modulated electronically with TTL signals. Two-beam technique has been used with convergence angle 30o and PC controlled incident beam plane rotation 0-360o. Optical system consists of beam splitter, 40mm focus length forming cylindrical lens and 40mm focusing lens. Characteristic parameters of experimental equipment are following: spot size - 50-200 micrometers, direct laser writing area, limited by x-y positioning system, was 70mm x 70mm, number of writing head rotation positions up to 256 (8 bit), time of each exposure - 1-1000 msec. As the recording material we have used AsxSySe1-x chalcogenide glass material. Diffraction efficiency of written gratings in the material in dot-matrix regime exceeds 25%. Original method for surface relief enhancement by etching and subsequent electroplating has been developed. Special PC controlled device for thermal imprinting of relief holograms on the metallized polyamide film has been built. Measurements of light transmission, reflection, and diffraction phenomena of laser beams in processed chalcogenide materials are discussed.
{"title":"Dot-matrix holographic recording in amorphous chalcogenide films","authors":"A. Bulanovs, Vjacheslavs Gerbreders, Valfrids Paschkevich, J. Teteris","doi":"10.1117/12.726405","DOIUrl":"https://doi.org/10.1117/12.726405","url":null,"abstract":"We have developed PC controlled dot-matrix holographic recording system based on the CW diode pumped YAG:Nd SHG laser (wavelength 532 nm, power 30mW,) modulated electronically with TTL signals. Two-beam technique has been used with convergence angle 30o and PC controlled incident beam plane rotation 0-360o. Optical system consists of beam splitter, 40mm focus length forming cylindrical lens and 40mm focusing lens. Characteristic parameters of experimental equipment are following: spot size - 50-200 micrometers, direct laser writing area, limited by x-y positioning system, was 70mm x 70mm, number of writing head rotation positions up to 256 (8 bit), time of each exposure - 1-1000 msec. As the recording material we have used AsxSySe1-x chalcogenide glass material. Diffraction efficiency of written gratings in the material in dot-matrix regime exceeds 25%. Original method for surface relief enhancement by etching and subsequent electroplating has been developed. Special PC controlled device for thermal imprinting of relief holograms on the metallized polyamide film has been built. Measurements of light transmission, reflection, and diffraction phenomena of laser beams in processed chalcogenide materials are discussed.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128198788","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}
I. Šimkienė, J. Sabataitytė, A. Rėza, A. Suchodolskis, G. Babonas
Composite system of iron porphyrin (FeTPPS) on aminosilanized Si substrates was investigated by studies of surface morphology and optical response. Aminofunctionalized siloxane films on silicon substrates were produced from different sol-gel precursors prepared from 3-aminopropyltriethoxysilane (APTES) dissolved in water, ethanol and acetone. Immersion technique was used for the formation of APTES films. Aqueous solutions of FeTPPS were deposited on aminosilanized Si substrates. Topographic features of nanostructures in composite FeTPPS/APTES/Si system were investigated by atomic force microscopy (AFM) technique. High-resolution phase contrast imaging revealed the substructure of siloxane films on silicon substrates and nanoaggregates of FeTPPS immobilized on aminosilanized Si surface. Spectroscopic ellipsometry measurements were carried out in the region 1-5 eV in order to characterize the siloxane films and composite structures. The analysis of obtained results allowed one to conclude that FeTPPS molecules were attached to the surface by covalent bonds between the functional group of sulfonic acid SO3- of iron porphyrin and (-NH2H+)-group of APTES.
{"title":"Studies of composite system of iron porphyrin immobilized on aminosilanized Si","authors":"I. Šimkienė, J. Sabataitytė, A. Rėza, A. Suchodolskis, G. Babonas","doi":"10.1117/12.726485","DOIUrl":"https://doi.org/10.1117/12.726485","url":null,"abstract":"Composite system of iron porphyrin (FeTPPS) on aminosilanized Si substrates was investigated by studies of surface morphology and optical response. Aminofunctionalized siloxane films on silicon substrates were produced from different sol-gel precursors prepared from 3-aminopropyltriethoxysilane (APTES) dissolved in water, ethanol and acetone. Immersion technique was used for the formation of APTES films. Aqueous solutions of FeTPPS were deposited on aminosilanized Si substrates. Topographic features of nanostructures in composite FeTPPS/APTES/Si system were investigated by atomic force microscopy (AFM) technique. High-resolution phase contrast imaging revealed the substructure of siloxane films on silicon substrates and nanoaggregates of FeTPPS immobilized on aminosilanized Si surface. Spectroscopic ellipsometry measurements were carried out in the region 1-5 eV in order to characterize the siloxane films and composite structures. The analysis of obtained results allowed one to conclude that FeTPPS molecules were attached to the surface by covalent bonds between the functional group of sulfonic acid SO3- of iron porphyrin and (-NH2H+)-group of APTES.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130706328","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}
G. Juška, K. Arlauskas, K. Genevičius, N. Nekrašas, G. Sliaužys
We propose a double injection current transient technique to study the charge carrier mobilities and recombination in thin films of bulk heterojunction structures. This experimentally simple technique allows estimation of bimolecular recombination coefficient and charge carrier mobility, either of a sum of electron and hole mobilities in double injection into insulator mode, or the ambipolar mobility in semiconductor mode. The double injection current transient technique is used to study RRPHT/PCBM bulk heterojunction solar cells, and the obtained results are compared with results obtained using TOF and CELIV techniques.
{"title":"Plasma injection as techniques to study charge carrier transport and recombination in organic solar cells and LED's","authors":"G. Juška, K. Arlauskas, K. Genevičius, N. Nekrašas, G. Sliaužys","doi":"10.1117/12.726505","DOIUrl":"https://doi.org/10.1117/12.726505","url":null,"abstract":"We propose a double injection current transient technique to study the charge carrier mobilities and recombination in thin films of bulk heterojunction structures. This experimentally simple technique allows estimation of bimolecular recombination coefficient and charge carrier mobility, either of a sum of electron and hole mobilities in double injection into insulator mode, or the ambipolar mobility in semiconductor mode. The double injection current transient technique is used to study RRPHT/PCBM bulk heterojunction solar cells, and the obtained results are compared with results obtained using TOF and CELIV techniques.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"52 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133390904","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 had investigated photoelectrical and current transient properties of TlBr in the temperature region from -20 C up to +20 C, in which the effect of ionic conductivity changes significantly. The evaluated thermal activation energy value of conductivity of about 0.78 eV could stand for several mechanisms, e.g., electronic and ionic conductivity. From the spectral dependencies of photocurrent several defect-related maxima in the region between 1 and 2.5 eV were identified, being dependent on sample prehistory. Maximum at about 1.2 eV had appeared if the spectra were scanned from the high to the low quantum energies. Meanwhile the height of the maximum at about 2.1-2.2 eV used to decrease if the sample was kept biased for several hours. The transient photocurrent kinetics had demonstrated a complex behaviour that could be explained either by the combined trapping and/or recombination of light-generated carriers to the defect centres associated with potential inhomogeneities, followed by the growing ionic conduction or by a diffusion-related scattering variation in time. The evaluated thermal activation energy of the time constants of both processes was found to be 0.24 - 0.27 eV. The obtained results indicate that ionic conductivity can take place also at -20 C, though its influence is less because of the thermally activated character.
{"title":"Analysis of photoelectrical properties and current transient behaviour in TlBr","authors":"V. Kažukauskas, A. Jurgilaitis, J. Vaitkus","doi":"10.1117/12.726367","DOIUrl":"https://doi.org/10.1117/12.726367","url":null,"abstract":"We had investigated photoelectrical and current transient properties of TlBr in the temperature region from -20 C up to +20 C, in which the effect of ionic conductivity changes significantly. The evaluated thermal activation energy value of conductivity of about 0.78 eV could stand for several mechanisms, e.g., electronic and ionic conductivity. From the spectral dependencies of photocurrent several defect-related maxima in the region between 1 and 2.5 eV were identified, being dependent on sample prehistory. Maximum at about 1.2 eV had appeared if the spectra were scanned from the high to the low quantum energies. Meanwhile the height of the maximum at about 2.1-2.2 eV used to decrease if the sample was kept biased for several hours. The transient photocurrent kinetics had demonstrated a complex behaviour that could be explained either by the combined trapping and/or recombination of light-generated carriers to the defect centres associated with potential inhomogeneities, followed by the growing ionic conduction or by a diffusion-related scattering variation in time. The evaluated thermal activation energy of the time constants of both processes was found to be 0.24 - 0.27 eV. The obtained results indicate that ionic conductivity can take place also at -20 C, though its influence is less because of the thermally activated character.","PeriodicalId":273853,"journal":{"name":"International Conference on Advanced Optical Materials and Devices","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128290136","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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