Abstract
We demonstrate working prototypes of a GaInNAs-based solar cell lattice-matched to GaAs with photoresponse down to 1 eV. This device is intended for use as the third junction of future-generation ultrahigh-efficiency three- and four-junction devices. Under the AM1.5 direct spectrum with all the light higher in energy than the GaAs band gap filtered out, the prototypes have open-circuit voltages ranging from 0.35 to 0.44 V, short-circuit currents of 1.8 mA/cm2, and fill factors from 61% to 66%. The short-circuit currents are of principal concern: the internal quantum efficiencies rise only to about 0.2. We discuss the short diffusion lengths which are the reason for this low photocurrent. As a partial workaround for the poor diffusion lengths, we demonstrate a depletion-width-enhanced variation of one of the prototype devices that trades off decreased voltage for increased photocurrent, with a short-circuit current of 6.5 mA/cm2 and an open-circuit voltage of 0.29 V.
Original language | American English |
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Pages (from-to) | 409-415 |
Number of pages | 7 |
Journal | Journal of Crystal Growth |
Volume | 195 |
Issue number | 1-4 |
DOIs | |
State | Published - 1998 |
NREL Publication Number
- NREL/JA-520-24702
Keywords
- Diffusion length
- Dimethylhydrazine
- GaInAsN
- GaInNAs
- MOVPE
- Solar cells