High built-in potential and Voc of monocrystalline CdTe/MgCdTe double-heterostructure solar cells with p-type a-Si:H hole-contacts

High quasi-Fermi-level splitting in monocrystalline n-type CdTe/MgCdTe double-heterostructures can be effectively extracted using p-type a-Si:H contacts, achieving V
_oc
over 1 V. We show high-efficiency monocrystalline CdTe with V
_oc
around 1V, evidencing a built-in voltage between p-type a-Si:H and n-CdTe of 1.1 V using capacitance-voltage measurements.