DocumentCode :
2614250
Title :
The density of states (DOS) of i-layers in a Si:H based pin cells determined by CPM measurements
Author :
Rübel, H. ; Geyer, R. ; Scheppat, B. ; Lechner, P. ; Gorn, M. ; Kniffle, N.
Author_Institution :
Phototronics Solartech. GmbH, Putzbrunn, Germany
fYear :
1990
fDate :
21-25 May 1990
Firstpage :
1389
Abstract :
In a systematic study, the spectral distribution of the optical absorption coefficient within the subbandgap energy range was estimated. This was done by constant photocurrent method (CPM) measurements on glow-discharge-deposited a-Si based pin cells. Typical CPM spectra were evaluated for pin cells with thicknesses ranging from 0.5 μm to 10 μm measured in various bias modes. Bias-mode-dependent occupations and transitions involving defect states are considered for two representative cells (d=0.64 μm or ´thin´ and d=3.4 μm or ´thick´). The density of states of the thick cell shows a characteristic minimum in the defect-controlled energy region for positive bias voltages while the number of deep defect states remains constant, N(E)=(1.5-3)×1015 cm-3 . In the case of the thin cell, N(E) is on the order of 6×1015 cm-3
Keywords :
amorphous semiconductors; elemental semiconductors; hydrogen; silicon; solar cells; 0.5 to 10 micron; Si:H solar cells; amorphous semiconductor; bias modes; constant photocurrent method measurements; defect-controlled energy region; density of states; glow discharge deposition; optical absorption coefficient; pin cells; positive bias voltages; subbandgap energy range; Absorption; Density measurement; Energy measurement; Glass; Optical films; Optical sensors; Photoconductivity; Photonic band gap; Thickness measurement; Voltage control;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Photovoltaic Specialists Conference, 1990., Conference Record of the Twenty First IEEE
Conference_Location :
Kissimmee, FL
Type :
conf
DOI :
10.1109/PVSC.1990.111838
Filename :
111838
Link To Document :
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