Research On Perovskite Solar Cells With The Delafossite P-type Semiconductors

Perovskite solar cells(PSCs) have achieved unprecedented development within few years, and the highest efficiency that certified has currently reached 21%. However, the emerging problems of PSCs’ stability seriously hindered the industrialization of PSCs in the future. Recently an fully printable heterojunction(“n-p”) PSC made of “FTO/compact-TiO2/meso-TiO2/meso-ZrO2/meso-carbon” was reported with good stability, but this device had a relatively poor efficiency, and while the introduction of hole-selective contact into the device greatly improved its performance. Therefore, in my work, a series of p-type delafossite semiconductor oxides were firstly inserted into such an fully printable PSC to further improve its efficiency, which is divided in the following two aspects:(1) an improved “n-i-p” mesoscopic PSC adopting the structure of “FTO/compact-TiO2/meso-TiO2/meso-Al2O3/meso-CuAlO2/meso-carbon” has been raised to improve charge extraction. From the photoluminescence and electrochemical impedance studies, it has been proved that the inserted CuAlO2, acting as an efficient hole conductor, had a significant impact on charge collection of the devices. Synchronized improvements in the overall J-V parameters led to a high efficiency of 13.9%. Besides, benefiting from the good chemical stability of CuAlO2, the devices presented good stability.(2) Here, another CuCrO2 semiconductor was also inserted into this “n-p” mesoscopic structure. The photoluminescence and transient photovoltage decay measurements showed that the installed meso-CuCrO2 as a hole transfer highway, improved the efficiency of charge extraction. The efficiency of optimized device increased slightly to 12.6%. But the stability of CuCrO2 device decreased significantly, specific reasons need further deep study.