Performance enhancement of ZnO nanowires/PbS quantum dot depleted bulk heterojunction solar cells with an ultrathin Al_2O_3 interlayer  

作　　者：臧帅普 王莹琳 李美莹 苏蔚 安美琦 张昕彤 刘益春 

机构地区：[1]Center for Advanced Optoelectronic Materials Research, School of Physics, and Key Laboratory of UV-Emitting Materials and Technology of Chinese Ministry of Education, Northeast Normal University [2]National Demonstration Center for Experimental Physics Education, Northeast Normal University

出　　处：《Chinese Physics B》2018年第1期98-103,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.91233204,51372036,and 51602047);the Key Project of Chinese Ministry of Education(Grant No.113020A);the 111 Project,China(Grant No.B13013)

摘　　要：Depleted bulk heterojunction （DBH） PbS quantum dot solar cells （QDSCs）, appearing with boosted short-circuit current density （Jsc）, represent the great potential of solar radiation utilization, but suffer from the problem of increased interfacial charge recombination and reduced open-circuit voltage （Voc）. Herein, we report that an insertion of ultrathin A1203 layer （ca. 1.2 A thickness） at the interface of ZnO nanowires （NWs） and PbS quantum dots （QDs） could remarkably improve the performance of DBH-QDSCs fabricated from them, i.e., an increase of Voc from 449 mV to 572 mV, J^c from 21.90 mA/cm2 to 23.98 mA/cm2, and power conversion efficiency （PCE） from 4.29% to 6.11%. Such an improvement of device performance is ascribed to the significant reduction of the interfacial charge recombination rate, as evidenced by the light intensity dependence on Jsc and Voc, the prolonged electron lifetime, the lowered trap density, and the enlarged recombination activation energy. The present research therefore provides an effective interfacial engineering means to improving the overall performance of DBH-QDSCs, which might also be effective to other types of optoelectronic devices with large interface area.Depleted bulk heterojunction （DBH） PbS quantum dot solar cells （QDSCs）, appearing with boosted short-circuit current density （Jsc）, represent the great potential of solar radiation utilization, but suffer from the problem of increased interfacial charge recombination and reduced open-circuit voltage （Voc）. Herein, we report that an insertion of ultrathin A1203 layer （ca. 1.2 A thickness） at the interface of ZnO nanowires （NWs） and PbS quantum dots （QDs） could remarkably improve the performance of DBH-QDSCs fabricated from them, i.e., an increase of Voc from 449 mV to 572 mV, J^c from 21.90 mA/cm2 to 23.98 mA/cm2, and power conversion efficiency （PCE） from 4.29% to 6.11%. Such an improvement of device performance is ascribed to the significant reduction of the interfacial charge recombination rate, as evidenced by the light intensity dependence on Jsc and Voc, the prolonged electron lifetime, the lowered trap density, and the enlarged recombination activation energy. The present research therefore provides an effective interfacial engineering means to improving the overall performance of DBH-QDSCs, which might also be effective to other types of optoelectronic devices with large interface area.

关 键 词：interface charge recombination A1203 interlayer PASSIVATION PbS quantum dots 

分 类 号：O4[理学—物理]