Yan Lei,Ruijuan Qi,Jinpeng Wu,Haodan Guo,Xiangrong Li,Yanyan Fang,Dongmei Xie,Yuan Lin
The III-V group colloidal quantum dots (CQDs) have been successfully synthesized with stable and low-cost chemical reagents recently, but they are rarely used for solid state solar cells due to the poor charge carrier transfer in solid films. In this work, the surface of InZnP (Zn doped InP) CQDs has been reconstructed with PbS via a chemical engineering strategy. Comparing with InZnP CQDs, the long carbon chain ligands capped on the InZnP@PbS CQDs surface can be easily exchanged with small molecules. By capping the mercaptopropionic acid (MPA) onto the InZnP@PbS CQDs surface, the electrical coupling between the InZnP@PbS CQDs has been established, and the photoinduced charge carrier transfer has been significantly enhanced. Based on the above CQDs, solid state solar cell devices are assembled, achieving about 1.5% of power conversion efficiency (PCE). The photoelectric performances of the fabricated solar cells almost do not decay after 150 days storage. Current work may provide a new way for III-V group CQDs application in solution-processed optoelectronics .
Owing to their environmentally friendly characteristic, InP-based quantum dots (QDs) show great potential in various fields as an alternative to Cd-based QDs. However, the current mainstream synthesis process, the (TMS)3P-based injection method, still faces many challenges, such as the high cost of (TMS)3P and complex temperature control. In contrast, the solvothermal method is considered to be more feasible and reproducible. Despite its potential advantages, little has been done to understand how the precursors influence the synthesis of InP QDs using the solvothermal method. In this research, InZnP/ZnS QDs were synthesized using practical phosphorus precursors (DEA)3P or (DMA)3P. Through the feasible regulation of zinc, indium, phosphorus and sulfur precursors, the band gap of the QDs could be widely and accurately tuned, and a much wider photoluminescence wavelength ranging from 484 nm to 651 nm could be achieved. Furthermore, InI3 and InBr3 contributed to the blueshift in the PL wavelengths, and the combination of (DEA)3P, (DMA)3P, n-DDT and t-DDT refined the PL wavelength with a small tuning gap of 5 nm.
Yan Lei,Ruijuan Qi,Longyan Gu,Haodan Guo,Xiangrong Li,Yanyan Fang,Dongmei Xie,Zhi Zheng,Yuan Lin
Colloidal quantum dots (CQDs) are promising materials for building next-generation solution-processed, high-performance, and low-cost optoelectronic devices. The photoelectric properties of the resulting films are not only determined by the intrinsic characteristics of the CQDs but are also significantly affected by the electrical coupling between them. However, enhancing the electrical coupling in CQD-based films is still a big challenge. In this work, a two-step ligand exchange strategy has been conducted to solve the above issue, where the InZnP@PbS CQDs have been used as the case. First, the Meerwein salt (Et 3 OBF 4 ) solution in N, N -dimethylformamide (DMF) has been employed to peel off the native ligands that are strongly capped on the surface of oil-soluble CQDs, resulting in a neat surface. Second, iodide ions are linked to the neat surface of the CQDs to narrow the distance between them and passivate their defects, establishing strong electrical coupling. Transient surface photovoltage (TSPV) and photo-conductance tests confirm that the resulting InZnP@PbS–I CQDs films possess good photoelectric properties and stability. In the fabricated solid-state solar cells, 3.1 % of the photoelectric conversion efficiency (PCE) has been achieved under 1 sun. The current results are outstanding for III-V group CQD-based all solid-state solar cells.
危险品化学品经营许可证（带存储）