CdSe quantum dot cathode buffer for inverted organic bulk hetero-junction solar cells

► A cathode buffer layer of CdSe QD is introduced in P3HT:ICBA IBHJ solar cells. ► The PCE is then increased from 4.8% to 5.2% as a result of the reduction of work function of cathode. ► CdSe QD layer retards Cs diffusion into active layer and thus improves the environmental stability of OPV.