Abstract
A study of Ga1-xInxNyAs1-y solar cells shows that nitrogen degrades the solar cells even for very small nitrogen concentrations. By comparing the properties of p-on-n and n-on-p Ga1-xInxNyAs1-y cells as a function of y, we find that the n-on-p cells show a more abrupt decrease in the open-circuit voltage and greater decrease of the photocurrent. The asymmetry in the performance of the cellsreflects the differences observed for electrons and holes in Ga1-xInxNyAs1-y. The electron mobility is degraded much more than the hole mobility when nitrogen is added to GaAs, implying that the electron diffusion length should be degraded more than the hole diffusion length. An electron trap (observed by deep-level transient spectroscopy) affects p-type GaNyAs1-y more than n-type GaNyAs1-y,consistent with the observation that the open-circuit voltage of n-on-p cells decreases more than that of p-on-n cells. The effect of nitrogen on GaNAs cells is shown to be much greater than expected for an isoelectronic impurity.
Original language | American English |
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Number of pages | 7 |
State | Published - 2005 |
Event | 31st IEEE Photovoltaics Specialists Conference and Exhibition - Lake Buena Vista, Florida Duration: 3 Jan 2005 → 7 Jan 2005 |
Conference
Conference | 31st IEEE Photovoltaics Specialists Conference and Exhibition |
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City | Lake Buena Vista, Florida |
Period | 3/01/05 → 7/01/05 |
NREL Publication Number
- NREL/CP-520-37361
Keywords
- deep level transient spectroscopy (DLTS)
- isoelectronic impurity
- nitrogen concentration
- open-circuit voltages
- PV
- solar cells