Effects of Defect Density and Compositional Grading on GaAsP Photovoltaic Performance

M. W. Wanlass, K. A. Emery, M. M. AL-Jassim, A. R. Mason

Research output: Contribution to conferencePaperpeer-review

5 Scopus Citations


The photovoltaic performance of n** plus p/p** plus GaAs//0//. //7//4P//0//. //2//6 shallow homojunctions is studied as a function of the dislocation density in the vicinity of the n** plus /p junction. Compositionally graded GaAsP/GaAs heterostructures grown by atmospheric-pressure metalorganic vapor phase epitaxy (APMOVPE) are used to produce shallow-homojunction devices with dislocation densities that vary over a wide range. The device structures are characterized and compared using optical microscopy, electron probe microanalysis, electron beam induced current, transmission electron microscopy, light J-V, dark J-V, and external quantum efficiency. In general, fewer compositional steps and thinner grades resulted in rougher surfaces, higher defect densities, and lower conversion efficiencies. Strong correlations are seen among the grading structure, dislocation configuration, surface morphology and solar cell characteristics. Thin compositional grades of the proper configuration are found to reduce the threading dislocation density to less than 10**6 cm**-**2.

Original languageAmerican English
Number of pages6
StatePublished - 1987
EventNineteenth IEEE Photovoltaic Specialists Conference-1987 - New Orleans, Louisiana
Duration: 4 May 19878 May 1987


ConferenceNineteenth IEEE Photovoltaic Specialists Conference-1987
CityNew Orleans, Louisiana

NREL Publication Number

  • ACNR/CP-213-9068


Dive into the research topics of 'Effects of Defect Density and Compositional Grading on GaAsP Photovoltaic Performance'. Together they form a unique fingerprint.

Cite this