Aging properties of high power laser diode arrays analyzed by Fourier-transform photocurrent measurements

Tomm, Jens W.; Jaeger, A.; Bärwolff, A.; Elsaesser, Thomas; Gerhardt, A.; Donecker, J.

doi:10.1063/1.120066

Cited by 36 publications

(12 citation statements)

References 5 publications

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“…The optical absorption of the lc-Si:H intrinsic absorber layer of solar cells is measured by applying Fourier-transform photocurrent spectroscopy (FTPS) [15][16][17] to the pi-n solar cells. With this sensitive technique, the absorption coefficient in the energy range from sub-band gap to above the band gap can be determined over nine orders of magnitude by measuring the photogenerated current as a function of the photon energy.…”

Section: Methodsmentioning

confidence: 99%

Influence on cell performance of bulk defect density in microcrystalline silicon grown by VHF PECVD

Gordijn

Hodakova

Rath

et al. 2006

Journal of Non-Crystalline Solids

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Section: Methodsmentioning

confidence: 99%

Influence on cell performance of bulk defect density in microcrystalline silicon grown by VHF PECVD

Gordijn

Hodakova

Rath

et al. 2006

Journal of Non-Crystalline Solids

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“…Another technique is Fourier transform photocurrent spectroscopy (FTPS) that is based on recording the photocurrent action spectrum using a Fourier Transform Infrared spectrometer. FTPS is often used to determine low energy trap states in inorganic semiconductors . One should note that photocurrent‐based methods may be more sensitive than PDS but can only probe the absorptance of the photocurrent‐generating species.…”

Section: Introductionmentioning

confidence: 99%

Determining Ultralow Absorption Coefficients of Organic Semiconductors from the Sub‐Bandgap Photovoltaic External Quantum Efficiency

Kaiser

Zeiske

Meredith

et al. 2019

Advanced Optical Materials

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Energy states below the bandgap of a semiconductor, such as trap states or charge transfer states in organic donor–acceptor blends, can contribute to light absorption. Due to their low number density or ultrasmall absorption cross‐section, the absorption coefficient of these states is challenging to measure using conventional transmission/reflection spectrophotometry. As an alternative, the external quantum efficiency (EQE) of photovoltaic devices is often used as a representative of the absorption coefficient, where the spectral line shape of the EQE is considered to follow the absorption coefficient of the active layer material. Here, it is shown that the sub‐bandgap EQE is subject to thickness dependent low finesse cavity interference effects within the device—making this assumption questionable. A better estimate for the absorption coefficient is obtained when EQE spectra corresponding to different active layer thicknesses are fitted simultaneously for one attenuation coefficient using an iterative transfer matrix method. The principle is demonstrated for two model acceptor–donor systems (PCE12‐ITIC and PBTTT‐PC71BM) and accurate subgap absorption coefficients are determined. This approach has particular relevance for both understanding subgap states and their utilization in organic optoelectronic devices.

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“…Fourier Transform Photocurrent Spectroscopy (FTPS) 22,23 was carried out on the same samples than the dark-and photo-conductivity. The FTPS signal was measured with a Thermo Fisher iS50 FTIR spectrometer and a Stanford Research SR570 current preamplifier.…”

Section: Introductionmentioning

confidence: 99%

Effect of oxygen doping in microcrystalline SiGe p-i-n solar cells

Bidiville

Matsui

Kondo

2014

Journal of Applied Physics

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The effect of doping with oxygen the microcrystalline silicon-germanium absorber layer of single-junction p-i-n solar cells has been studied. In parallel, the absorber layer quality was measured by depositing absorber layers directly on glass and measuring their electrical properties. By doping the absorber layer with the optimum oxygen concentration (about 1.4×1019 cm−3), an increase in short-circuit current density of almost 4 mA/cm2 was achieved in 3 μm thick p-i-n solar cell. This effect is attributed to the oxygen doping compensating the space charges caused by the germanium dangling bonds rather than the direct defect passivation, as no drastic change in layer quality was measured.

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Aging properties of high power laser diode arrays analyzed by Fourier-transform photocurrent measurements

Cited by 36 publications

References 5 publications

Influence on cell performance of bulk defect density in microcrystalline silicon grown by VHF PECVD

Influence on cell performance of bulk defect density in microcrystalline silicon grown by VHF PECVD

Determining Ultralow Absorption Coefficients of Organic Semiconductors from the Sub‐Bandgap Photovoltaic External Quantum Efficiency

Effect of oxygen doping in microcrystalline SiGe p-i-n solar cells

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