Organometallic trihalide perovskite solar cells have attracted the researchers due to their easy fabrication, low cost and high power conversion efficiencies. Hole-conductor free perovskite solar cell is the most interesting structure to be commercialized due to its manufacturing simplicity, lower cost materials and higher stability compared to the other structures such as p-i-n and n-i-p structures [1-2]. The main issues of this type of solar cells are the poor fill factor and low power conversion efficiency due to the direct contact between TiO₂ and carbon, absence of hole transport layer and poor interfacing between TiO₂/perovskite interface. To overcome this problem, the influence ZrO₂ and spiro-OMeTAD and correlate them with the photovoltaic performance will be presented. Three different cells have been prepared and compared to each other, typically named “cell 1” without ZrO₂ spacer layer, “cell 2” with ZrO₂ spacer layer between mesoprous TiO₂/carbon electrode interface and “cell3” with perovskite doped spiro-OMeTAD with 50 wt%. Different photovoltaic performances were observed and enhancement of the fill factor has been achieved. The strength of our perovskite CH₃NH₃PbI₃ layer has been enhanced with a ratio of 10 wt% of PbCl₂, the HTM-free PSCs based on the incorporation ZrO₂ “cell 2” has a significant increase in the fill factor more than 0.49, and “cell 1” achieved a higher efficiency of 5.4 %.

References

1. Chenxi Zhang . Yudan Luo . Xiaohong Chen . Yiwei Chen . Zhuo Sun . Sumei Huang. Effective Improvement of the Photovoltaic Performance of Carbon-Based Perovskite Solar Cells by Additional Solvents, 2016, Nano-Micro Lett. 8(4):347–357.
2. Using a low-temperature carbon electrode for preparing hole-conductor-free perovskite heterojunction solar cells under high relative humidity. 2016, Nanoscale, 8, 7017

Figure 1: Schematic representation of the cell structure.