Abstract
The interface recombination velocity (IRV) at the interfaces in CdTe/MgxCd1-xTe double heterostructures (DHs) is studied using time-resolved photoluminescence. It is found that both thermionic emission and tunneling effects can cause photogenerated carrier loss over or through the Mgx Cd1-x Te barriers, either due to the low barrier potential or the thin barrier thickness. Thus, carrier lifetime measurements reveal only an effective IRV. The thermionic emission induced interface recombination can be distinguished by conducting temperature-dependent carrier lifetime measurements, and the tunneling induced IRV can be quantified by comparing samples with different barrier thicknesses. When both thermionic emission and tunneling effects are suppressed or even eliminated, the actual IRV (due to the recombination at the DH interface trap states) is measured to be ∼1 cm/s, with a very long carrier lifetime of 3.6 μs achieved in the DHs.
Original language | English (US) |
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Article number | 7888444 |
Pages (from-to) | 913-918 |
Number of pages | 6 |
Journal | IEEE Journal of Photovoltaics |
Volume | 7 |
Issue number | 3 |
DOIs | |
State | Published - May 2017 |
Keywords
- Carrier lifetime
- CdTe
- interface recombination velocity (IRV)
- molecular beam epitaxy (MBE)
- solar cell
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering