ABSTRACT
CdTe/MgCdTe double heterostructures (DHs) are grown on InSb substrates using molecular beam epitaxy and reveal strong photoluminescence with over double the intensity of a GaAs/AlGaAs DH with an identical layer structure design grown on GaAs. Time-resolved photoluminescence of the CdTe/MgCdTe DH gives a Shockley-Read-Hall recombination lifetime of 86 ns, which is more than one order of magnitude longer than that of typical polycrystalline CdTe films. These findings indicate that monocrystalline CdTe/MgCdTe DHs effectively reduce surface recombination, have limited nonradiative interface recombination, and are promising for solar cells that could reach power conversion efficiencies similar to that of GaAs.
The authors would like to thank Bas A. Korevaar and Aharon Yakimov at General Electric Global Research Center and Su Lin at ASU for assistance with TRPL measurements. This work was partially supported by AFOSR (Grant No. FA9550-12-1-0444), Science Foundation Arizona (Grant No. SRG 0339-08), and NSF (Grant No. 1002114). M.J.D. was supported by the National Science Foundation Graduate Research Fellowship (Grant No. DGE-0802261) and A.P.K. is supported by the Bisgrove Postdoctoral Scholars program. The authors gratefully acknowledge the use of facilities in the LeRoy Eyring Center for Solid State Science at Arizona State University.
