Processing- and radiation-produced defects in InP solar cells

The detection and characterization of processing- and radiation-induced defects in p-type InP using deep level transient spectroscopy (DLTS) are described. Annealing effects are discussed and initial recovery of critical cell parameters is correlated with anneal of dominant defects. It is shown that DLTS spectra differ for implanted and epitaxial junctions. The implanted diodes do not show the H4 (0.38 eV) level, casting doubt on the Frenkel pair, V/sub p/-P/sub i/, identity assignment. Carrier loss and degradation of V/sub oc/, I/sub sc/, and cell efficiency correlate with the production of dominant hole traps H4 and H3. Observed recovery correlates with anneal of H4 and H3.<
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