TY - JOUR
T1 - Improving carrier extraction in a PbSe quantum dot solar cell by introducing a solution-processed antimony-doped SnO2 buffer layer
AU - Chen, Zihan
AU - Zhang, Zhilong
AU - Yang, Jianfeng
AU - Chen, Weijian
AU - Teh, Zhi Li
AU - Wang, Dian
AU - Yuan, Lin
AU - Zhang, Jianbing
AU - Stride, John A.
AU - Conibeer, Gavin J.
AU - Patterson, Robert J.
AU - Huang, Shujuan
PY - 2018/10/7
Y1 - 2018/10/7
N2 - Solution-processable lead selenide (PbSe) colloidal quantum dots (QDs) are promising candidates for photovoltaics due to their efficient multiple exciton generation and carrier transport. However, despite these advantages, currently the best PbSe QD solar cells (QDSCs) still have short-circuit current densities (JSC) of about 25 mA cm-2. Here, we report the introduction a solution-processed trivalent antimony-doped tin oxide buffer layer at the interfaces in the device, which led to significant improvement in the JSC. Consistent with the optical simulations, the external quantum efficiency of the devices was improved in a region corresponding to the PbSe QD/buffer layer interfaces (400-600 nm), implying enhanced electron extraction. The improved performance is attributed to optimized gradient energy level alignment and shunt blocking at the interfaces. With this simple interfacial treatment, the JSC of the champion device was increased significantly to 26.7 mA cm-2, a more than 8% improvement compared to the control device. A further increase in the fill factor was also observed, leading to an over 11% improvement in the champion power conversion efficiency, from 7.1% to 7.9%. This work offers a simple method for interfacial engineering that led to PbSe QDSCs with efficiencies that are among the highest reported in the literature.
AB - Solution-processable lead selenide (PbSe) colloidal quantum dots (QDs) are promising candidates for photovoltaics due to their efficient multiple exciton generation and carrier transport. However, despite these advantages, currently the best PbSe QD solar cells (QDSCs) still have short-circuit current densities (JSC) of about 25 mA cm-2. Here, we report the introduction a solution-processed trivalent antimony-doped tin oxide buffer layer at the interfaces in the device, which led to significant improvement in the JSC. Consistent with the optical simulations, the external quantum efficiency of the devices was improved in a region corresponding to the PbSe QD/buffer layer interfaces (400-600 nm), implying enhanced electron extraction. The improved performance is attributed to optimized gradient energy level alignment and shunt blocking at the interfaces. With this simple interfacial treatment, the JSC of the champion device was increased significantly to 26.7 mA cm-2, a more than 8% improvement compared to the control device. A further increase in the fill factor was also observed, leading to an over 11% improvement in the champion power conversion efficiency, from 7.1% to 7.9%. This work offers a simple method for interfacial engineering that led to PbSe QDSCs with efficiencies that are among the highest reported in the literature.
UR - http://www.scopus.com/inward/record.url?scp=85054133047&partnerID=8YFLogxK
U2 - 10.1039/c8tc03599g
DO - 10.1039/c8tc03599g
M3 - Article
AN - SCOPUS:85054133047
SN - 2050-7534
VL - 6
SP - 9861
EP - 9866
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
IS - 37
ER -