ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
A multijunction structure, Ga(As,P)/GaAs/Ga(As,P)/n+-GaAs, and a conventional Ga(As,P)/n+-GaAs structure were compared using a variety of photoelectrochemical (PEC) techniques. The samples were grown, using metalorganic chemical vapor deposition, on n+-GaAs substrates with an initial graded region with gradually varying composition. The conventional sample had a terminating top layer with constant composition GaAs0.45 P0.55. In the multijunction sample, a GaAs region was introduced between the graded region and the top layer, resulting in an interface with an abrupt heterojunction. The multijunction electrode showed several unusual PEC features, including a very low dark current over a wide potential region, both cathodic and anodic photoeffects, and a pronounced decrease in photoactivity when going to shorter wavelengths. A plausible interpretation is presented, also providing insights into the effects of graded regions versus heterojunctions, and illustrating the value of PEC studies in probing the interior of complex semiconductor materials.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.343025
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