Design of high efficiency and high stability organic polymer/inorganic quantum dot hybrid solar cell via small molecule bridge

Abstract

Solution processed semiconductors are promising materials to realize optoelectronic devices that high performance and inexpensive manufacturing. Among them, the hybrid photovoltaics using the organic polymers and inorganic quantum dots as a photo-active materials have attracted many researchers because they can achieve the many advantages of both materials. Unfortunately, the improvement of power conversion efficiencies(PCEs) in the CQDs/polymer hybrid photovoltaic devices are still sluggish. Here, we studied the theoretical limitation of the PCEs in the CQDs/organic hybrid photovoltaic devices and demonstrate the high performance and high stability CQDs/polymer hybrid photovoltaic devices that synergistically exploits the benefits of CQDs and polymers in photovoltaics. In this paper, we introduce the small molecules into the organic layer as auxiliary n-type acceptor and these promoted exciton dissociation at the CQDs:organic interface, and also improve carrier transport. Also these small molecule bridge strategy contributes to suppressing geminate recombination and complements absorption of the QD layer across the visible and near-infrared solar spectrum. Finally, we demonstrate the high performance - exceed an AM1.5 PCE of 13.1% - and high stable - retained over 80% of their initial PCE following 150 hours of continuous operation at the maximum power point, while operating unencapsulated under 1 sum irradiation – CQDs/organic hybrid photovoltaic devices.