| 초록 |
Today's perovskite solar cells's power conversion efficiency(PCE) has been increased up to 22.1%. Most of perovskite solar cells use TiO2 for electron transport layer (ETL). But in this studies we used ZnO for ETL. ZnO has larger band gap than TiO2. So ZnO films can transmit more sunlight than TiO2 films. Also ZnO films can be obtained at low temperature (~350°C). Despite of these benefit of ZnO films the reason why we did not use ZnO is because of unstability of perovskite films deposited on ZnO films. The ZnO films' surface has lots of hydroxyl, so the perovskite films are very unstable on ZnO films. But we can solve these problems by pre-annealing. Pre-annealing can stabilize the perovskite films deposited on ZnO. Moreover, pre-annealing helps to increase the size of the perovskite grains and contributes to increased PCE. |
