All-polymer organic solar cells with nano-to-micron hierarchical morphology and large light receiving angle

Distributed photovoltaics in living environment harvest the sunlight in different incident angles throughout the day. The development of planer solar cells with large light-receiving angle can reduce the requirements in installation form factor and is therefore urgently required. Here, thin film organic photovoltaics with nano-sized phase separation integrated in micro-sized surface topology is demonstrated as an ideal solution to proposed applications. All-polymer solar cells, by means of a newly developed sequential processing, show large magnitude hierarchical morphology with facilitated exciton-to-carrier conversion. The nano fibrilar donor-acceptor network and micron-scale optical field trapping structure in combination contributes to an efficiency of 19.06% (certified 18.59%), which is the highest value to date for all-polymer solar cells. Furthermore, the micron-sized surface topology also contributes to a large light-receiving angle. A 30% improvement of power gain is achieved for the hierarchical morphology comparing to the flat-morphology devices. These inspiring results show that all-polymer solar cell with hierarchical features are particularly suitable for the commercial applications of distributed photovoltaics due to its low installation requirement. A large light-receiving angle in planar solar cells is crucial for flexible installation of distributed photovoltaics. Here, authors report sequential-processed all-polymer solar cells with nano-sized phase separation integrated in micro-sized surface topology and maximum efficiency of over 19%.

Automated summary

This study demonstrates a thin film organic photovoltaic technology integrated with nano-sized phase separation and micro-sized surface topology, which can harvest solar energy at different incident angles throughout the day. The all-polymer solar cells with hierarchical morphology and large light-receiving angle are suitable for commercial applications of distributed photovoltaics.