Trap-Assisted Transport and Non-Uniform Charge Distribution in Sulfur-Rich PbS Colloidal Quantum Dot-based Solar Cells with Selective Contacts

详细信息    查看全文

• 作者：Victor Malgras ; Guanran Zhang ; Andrew Nattestad ; Tracey M. Clarke ; Attila J. Mozer ; Yusuke Yamauchi ; Jung Ho Kim
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：December 9, 2015
• 年：2015
• 卷：7
• 期：48
• 页码：26455-26460
• 全文大小：383K
• ISSN：1944-8252

文摘

This study reports evidence of dispersive transport in planar PbS colloidal quantum dot heterojunction-based devices as well as the effect of incorporating a MoO₃ hole selective layer on the charge extraction behavior. Steady state and transient characterization techniques are employed to determine the complex recombination processes involved in such devices. The addition of a selective contact drastically improves the device efficiency up to 3.15% (especially due to increased photocurrent and decreased series resistance) and extends the overall charge lifetime by suppressing the main first-order recombination pathway observed in device without MoO₃. The lifetime and mobility calculated for our sulfur-rich PbS-based devices are similar to previously reported values in lead-rich quantum dots-based solar cells. Nevertheless, strong Shockley鈥揜ead鈥揌all mechanisms appear to keep restricting charge transport, as the equilibrium voltage takes more than 1 ms to be established.