Specific features of light current-voltage characteristics of p-i-n structures based on amorphous silicon in the case of the tunnel-drift mechanism of dark current transport

Journal Article · Sat Nov 15 04:00:00 EST 2008 · Semiconductors

DOI:https://doi.org/10.1134/S1063782608110171· OSTI ID:21255559

Current-voltage (I-V) characteristics of p-i-n structures based on amorphous silicon ({alpha}-Si:H) with small hole diffusion lengths (shorter than the thickness of the i-layer of a p-i-n structure) have been experimentally studied with and without illumination. It is shown that forward I-V characteristics of structures of this kind can be described by a dependence inherent in diodes, with a diode ideality factor two-three times the maximum value of 2, theoretically predicted for generation-recombination currents in p-n junctions. The dark current is always substantially lower than the photocurrent in a cell biased with a voltage approximately equal to the opencircuit voltage of the photocell. Dark currents cannot contribute to the I-V characteristic under illumination. The photocurrent decreases with increasing photovoltage at a bias lower than the open-circuit voltage because of a decrease in the collection coefficient and the increasingly important role of back diffusion of electrons into the p-contact, rather than as a result of the dark injection. In the case of biases exceeding the open-circuit voltage, back diffusion becomes the predominant component of the current.

• OSTI ID: 21255559
• Journal Information: Semiconductors, Journal Name: Semiconductors Journal Issue: 11 Vol. 42; ISSN SMICES; ISSN 1063-7826
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DIFFUSION
DIFFUSION LENGTH
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
ELECTRONS
HOLES
ILLUMINANCE
LAYERS
P-N JUNCTIONS
PHOTOELECTRIC CELLS
RECOMBINATION
SILICON
TUNNEL EFFECT