Front and Back Interface Recombination of MZO/CdTe/Te Solar Cells

Interfacial recombination parameters of MgZnO/CdTe solar cells and polycrystalline heterostructures were determined from time-resolved photoluminescence measurements on CdTe absorbers with a thickness range from 0.4 to 2.0 μm. Excitation incident from each side of the structure revealed significant differences in front and back interface quality. The bulk lifetime in the absorber was ~6 ns, and the electron mobility ~25 cm2/Vs. A comparison to similar structures fabricated on glass without a transparent conducting oxide demonstrated that the diode field plays a significant role in the decay rate observed. TRPL measurements with and without Te at the back showed that lifetime was somewhat dependent on the presence of a Te buffer layer likely due to changes in interface recombination at the CdTe/Te interface.