Hole Transport Material for Passivated Back Contacts on CdTe Solar Cells

Surface chemical treatments of the back surface of CdTe are combined with the use of an organic hole transport material for the improvement of back contact passivation. Photovoltaic devices using these modified back contacts show an increase in photoluminescence intensity and open circuit voltage, indicating an improvement in hole selectivity as compared to unpassivated Au back contacts. Solar cells with surfaces treated to be Cd-rich and a poly(triaryl amine) (PTAA) as a hole transport material show an increased open circuit voltage of 858 mV.