posted on 2021-08-30, 19:33authored byHailu Wang, Fang Wang, Tengfei Xu, Hui Xia, Runzhang Xie, Xiaohao Zhou, Xun Ge, Weiwei Liu, Yicheng Zhu, Liaoxin Sun, Jiaxiang Guo, Jiafu Ye, Muhammad Zubair, Man Luo, Chenhui Yu, Deyan Sun, Tianxin Li, Qiandong Zhuang, Lan Fu, Weida Hu, Wei Lu
Hot
carrier harvest could save 30% energy loss in solar cells.
So far, however, it is still unreachable as the photoexcited hot carriers
are short-lived, ∼1 ps, determined by a rapid relaxation process,
thus invalidating any reprocessing efforts. Here, we propose and demonstrate
a feasible route to reserve hot electrons for efficient collection.
It is accomplished by an intentional mix of cubic zinc-blend and hexagonal
wurtzite phases in III–V semiconductor nanowires. Additional
energy levels are then generated above the conduction band minimum,
capturing and storing hot electrons before they cool down to the band
edges. We also show the superiority of core/shell nanowire (radial
heterostructure) in extracting hot electrons. The strategy disclosed
here may offer a unique opportunity to modulate hot carriers for efficient
solar energy harvest.