- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Pressure-enhanced electronic coupling of highly passivated quantum dot films to improve photovoltaic performance
摘要： PbS colloidal quantum dot solar cells (CQDSCs) have recently achieved remarkable performance enhancement due to the development of the phase-transfer ligand exchange (PTLE) method. However, the lack of compact packing of the PTLE-passivated CQDs impairs the interdot electronic coupling and thereby severely restricts further improvement in performance. To address this electronic coupling issue, we report a simple yet effective process of external pressure (0–2 MPa). We ?nd that the interdot distance is reduced after the application of the pressure. Both optical and electrical measurements clearly demonstrate that the distance reduction can effectively strengthen the interdot electronic coupling, thus promoting the carrier transport of the CQD layer. However, too much pressure (>2 MPa) could accelerate the detrimental carrier recombination processes of CQDSCs. Accordingly, by optimizing the carrier transport and recombination processes, we achieve the maximum power conversion ef?ciency of 8.2% with a moderate pressure of 1.5 MPa, which is 25.5% higher than the solar cell without the external pressure. This effective strategy of external pressure could also be applied to other CQD-based optoelectronic devices to realize a better device performance.
关键词： external pressure,PbS colloidal quantum dot solar cells,phase-transfer ligand exchange,quantum dot films,Pressure-enhanced electronic coupling,photovoltaic performance
更新于2025-09-12 10:27:22
-
Manipulation of Phase-Transfer Ligand-Exchange Dynamics of PbS Quantum Dots for Efficient Infrared Photovoltaics
摘要： Chemical surface treatment of colloidal quantum dots (CQDs) by phase-transfer ligand exchange (PTLE) is essential to implement highly densified, well-passivated CQD films for optoelectronic applications, such as infrared photovoltaics, light-emitting diodes and photodetectors. The PTLE, however, involves parallel and interactional processes of ligand exchange, phase transfer, and surface passivation of CQDs, which renders the optimization of PTLE still challenging. Herein, we explored the action mechanism of a widely-used additive, ammonium acetate (AA), on the PTLE of PbS CQDs in order to recognize the dynamic balance during the PTLE process and its impact on the performance of colloidal quantum dot solar cells (CQDSCs). Our research definitely shows that AA additive can modify the dynamics of PTLE by participating in all the three processes, and the amount of AA significantly influences the defect passivation and colloidal stability of PbS CQDs. At an appropriate concentration (~50 mM) of AA, PbS CQDs are well iodide-passivated by the PTLE, and the fabricated CQDSCs achieve the PCE of ~10% associated with the improved carrier transport and the reduced trap-assisted carrier recombination. However, excessive AA causes the trace residual AA on the CQD surface, resulting in the insufficient surface passivation of PbS CQDs and trap issues of CQDSCs. The double-edged sword effect of AA additive on the PTLE, demonstrated in our work, suggests that realizing the dynamic balance of different processes during PTLE is crucial for the further performance promotion of CQDSCs.
关键词： infrared photovoltaics,ammonium acetate,phase-transfer ligand exchange,colloidal quantum dots,surface passivation
更新于2025-09-11 14:15:04