Dynamical properties and charge accumulation in solar cells with embedded GaSb quantum dots
Abstract
We studied the dynamical properties of quantum dot solar cells in which GaSb quantum dots (QDs) were embedded in the middle part of an undoped layer sandwiched by n- and p-layers. Three kinds of GaSb QDs with GaAs or AlGaAs as a barrier material for QDs were prepared for comparison of their properties. The capacitance C was measured as a function of the frequency f in the ranges between 5 kHz and 3 MHz under different illumination conditions. A rise in capacitance in response to illumination was observed in all the samples, showing that photogenerated carriers (or holes) contribute to the dynamical properties of solar cell devices. Differences in capacitance change among the three samples are observed in magnitude and its frequency dependence. We discuss them in terms of the difference in dynamical processes, specifically the thermal escape rate of holes in QDs.
- Publication:
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Japanese Journal of Applied Physics
- Pub Date:
- August 2018
- DOI:
- 10.7567/JJAP.57.08RF10
- Bibcode:
- 2018JaJAP..57hRF10N