CsPbI <sub>3-</sub> perovskite quantum dot solar cells: unlocking their potential through improved absorber layer characteristics and reduced defects
Nikhil Shrivastav, Jaya Madan, Mustafa K. A. Mohammed, M. Khalid Hossain, Rahul Pandey
Abstract
Abstract Perovskite quantum dots (CsPbI 3 -PQDs), a translucent material, have gained great interest in the PV industries owing to their unified virtues of perovskites and quantum dots. However, researchers have found that perovskite solar cells (PSCs) suffer from issues like low stability at high relative humidity, energy states imbalance, severe hysteresis, and an easy decomposition under ultraviolet (UV) radiation that severely restrict their industrialization. Quantum dots (QDs) are excellent materials with numerous admirable traits that have been extensively employed in PSCs to overcome the aforementioned problems. To achieve high performance of the examined device, the CsPbI 3 -PQDs has been stacked between two charge transport layers, i.e., Cl@SnO 2 (to facilitate electrons towards cathode) and P 3 HT (to facilitate holes towards anode). In this context, study of variations in different parameters such as thickness and acceptor density of the CsPbI 3 -PQDs absorber layer has been done. After varying the thickness and acceptor density of the CsPbI 3 -PQDs layer, the cell’s performance is optimized at thickness of 400 nm and acceptor density of 1 × 10 17 /cm 3 delivering higher PV parameters power conversion efficiency (PCE):16.17%, open circuit voltage (V OC ):1.02 V, short circuit density (J SC ):18.06 mA cm −2 and fill factor (FF): 87.06% respectively. Thereafter, the effects of bulk defects in CsPbI 3 -PQDs and the interface between CsPbI 3 -PQDs and Cl@SnO 2 have been explored in this work. For the cell to work at its best, the bulk defect density and interface defect density, respectively, should not be more than 1 × 10 14 /cm 3 and 1 × 10 13 /cm 2 . Afterwards, a comprehensive study has been done by varying the front electrode transparency (from 40% to 95%) to improve the device performance. With 95% of front electrode transparency, the performance of device is improved due to increase in the photon coupling.