Abstract:
The carbon based hole transport material free perovskite solar cells (C-PSCs) that employ inorganic CsPbI2Br perovskite, have gained extensive attention. Two preparation methods for efficient and stable planar-heterojunction CsPbI2Br C-PSCs under fully ambient environment are presented. Firstly, by optimizing the type and dosage of antisolvent materials, CsPbI2Br C-PSCs with power conversion efficiency of 9.87% were successfully prepared by one-step solution method under the conditions of 800 μL antisolvent and 1.2 mol/L perovskite precursor solution concentration.In order to get rid of the dependence of one-step solution method on toxic antisolvent, the low-temperature pre-annealing process is introduced. By optimizing the pre-annealing time and temperature, as well as the concentration of perovskite precursor solution, the optimal efficiency of 10.52% is achieved with 80 ℃ pre-annealing temperature and 1.6 mol/L perovskite precursor solution concentration in fully ambient without anti-solvents. Meanwhile, the annealing temperature of CsPbI2Br perovskite is reduced to 240 ℃, and the unencapsulated device shows excellent stability in the ambient.
