Accurate analysis of electron transfer from quantum dots to metal oxides in quantum dot sensitized solar cells

• Electron transfer rate in quantum dot sensitized solar cells (QDSSCs) is analyzed.
• Maximum electron transfer rate is obtained for CdTe-SnO2 combination.
• Optimum diameter of QD is 2-5 nm, depending on the metal oxide-QD combination.
• Removal of the structural disorders increases the value of electron transfer rate.
• The obtained results could be used as a guide for the future design of QDSSCs.

Electron transfer rate from quantum dot (QD) to metal oxide (MO) in quantum dot sensitized solar cells (QDSSCs) has an important role in the efficiency. In this work, we analyse the electron transfer rate from CdSe, CdS and CdTe QDs to TiO2, ZnO and SnO2 MOs by extending the related equations with considering various effects, based on the Marcus theory. In this regard, the effects of QD diameter, QD–MO spacing, the crystalline defects, temperature, and the reorganizational energy, on the electron transfer rate are investigated. The results show that, the maximum electron transfer rate is achieved for CdTe QD with the mentioned three MOs. Moreover, in order to direct the designer to reach the appropriate QDs–MOs combinations for obtaining the maximum electron transfer rate, the average electron transfer rate for various combinations is calculated. For the verification of simulation method, a part of work has been compared with the previous experimental and theoretical results, which indicates the correctness of our simulation algorithm.