Achieving high open-circuit voltage in the PPV-CdHgTe bilayer photovoltaic devices on the basis of the heterojunction interfacial modification

On the basis of the surface modification of CdHgTe nanocrystals (NCs), a bilayer photovoltaic device composed of poly(p-phenylene-vinylene) (PPV) and CdHgTe NC heterojunction is prepared. The energy bands bend to the vacuum level through tuning the dipole moment of the CdHgTe NCs at the heterojunction interface and 0.3 eV energy band shifting is detected by the ultraviolet photoelectron spectrometer (UPS) measurement. As a result, open-circuit voltage (V-oc) of the photodiode can reach 1.4 V under AM 1.5G illumination (100 mW cm(-2)).