Efficient, Stable, Dopant‐Free Hole‐Transport Material with a Triphenylamine Core for CH3NH3PbI3 Perovskite Solar Cells

Abstract

AbstractA star‐shaped hole‐transporting material (HTM) using the triphenylamine (TPA) as the core named TP1 is designed and synthesized. The implementation of the new HTM in CH3NH3PbI3‐based perovskite solar cells exhibits an excellent overall power conversion efficiency (PCE) of 12.63 % without the use of any dopants and additives, which is comparable to the 14.93 % obtained using p‐doped spiro‐OMeTAD. Importantly, the devices based on TP1 show relatively stable device performance compared to spiro‐OMeTAD after aging in ambient air with 30 % relative humidity without encapsulation in the dark. The present results demonstrate that TPA could be an excellent building block to design dopant‐free HTMs for perovskite solar cells and holds promise to replace p‐doped spiro‐OMeTAD, which is important for the fabrication of cost‐effective and stable devices.