Department of Electrical and Computer Engineering, University of Toronto , 10 King's College Road, Toronto, Ontario M5S 3G4, Canada.
Nano Lett. 2017 Apr 12;17(4):2349-2353. doi: 10.1021/acs.nanolett.6b05241. Epub 2017 Mar 16.
Colloidal quantum dot (CQD) materials are of interest in thin-film solar cells due to their size-tunable bandgap and low-cost solution-processing. However, CQD solar cells suffer from inefficient charge extraction over the film thicknesses required for complete absorption of solar light. Here we show a new strategy to enhance light absorption in CQD solar cells by nanostructuring the CQD film itself at the back interface. We use two-dimensional finite-difference time-domain (FDTD) simulations to study quantitatively the light absorption enhancement in nanostructured back interfaces in CQD solar cells. We implement this experimentally by demonstrating a nanoimprint-transfer-patterning (NTP) process for the fabrication of nanostructured CQD solids with highly ordered patterns. We show that this approach enables a boost in the power conversion efficiency in CQD solar cells primarily due to an increase in short-circuit current density as a result of enhanced absorption through light-trapping.
胶体量子点（CQD）材料由于其可调带隙和低成本的溶液处理，在薄膜太阳能电池中受到关注。然而，CQD 太阳能电池在完全吸收太阳光所需的薄膜厚度上存在电荷提取效率低的问题。在这里，我们展示了一种通过在背界面处对 CQD 薄膜本身进行纳米结构化来增强 CQD 太阳能电池中光吸收的新策略。我们使用二维有限差分时域（FDTD）模拟来定量研究纳米结构化背界面在 CQD 太阳能电池中增强光吸收的效果。我们通过展示用于制造具有高度有序图案的纳米结构化 CQD 固体的纳米压印转移图案化（NTP）工艺来实现这一目标。我们表明，这种方法可以提高 CQD 太阳能电池的功率转换效率，主要是由于通过光捕获增强吸收导致短路电流密度增加。
