Solution synthesis and phase control of inorganic perovskites for high-performance optoelectronic devices

Abstract

An efficient method to synthesize well-crystallized inorganic cesium lead halide perovskites (CsPbX, X = I or Br) with high yield and high reproducibility was proposed. Notably, the as-prepared CsPbI in the yellow orthorhombic phase (y-CsPbI) can be easily converted to the black cubic perovskite phase CsPbI (b-CsPbI) after thermal annealing. Furthermore, two-terminal photodetectors and all-inorganic perovskite solar cells based on b-CsPbI were fabricated, exhibiting high performances.

Combination of solution-phase process and halide exchange for all-inorganic, highly stable CsPbBr3 perovskite nanowire photodetector

“…S4. The absorption edge of solution-phase synthesized CsPbI 3 NWs is located at 450 nm with a bandgap of 2.76 eV, which matches well with the previous report [34]. The absorption edge of W-CsPbBr 3 NWs after the accomplishment of halide substitution blue shifted to 385 nm, corresponding to a bandgap of 3.23 eV.…”

“…However, this method can only produce non-perovskite phase iodine-based perovskite nanowires. In order to achieve the transition from non-perovskite phase to perovskite phase, high temperature annealing (310-350°C) will be used and the yellow CsPbI 3 with nonperovskite phase can be transformed to the black CsPbI 3 with perovskite phase [34]. However, the high temperature annealing process results in many defects in nanowires, and the uniform heating at high temperature is very difficult.…”

Low Temperature Fabrication for High Performance Flexible CsPbI2Br Perovskite Solar Cells

“…The CsPbX 3 ‐based inorganic perovskites have been demonstrated to be another promising and novel candidates for photovoltaic applications . However, most reported high performance CsPbX 3 perovskite solar cells (PSCs) need to be prepared at high temperature (>250 °C) to overcome the crystallization energy barrier for the black cubic perovskite phase(α‐phase) . Such high heating temperature will lead to a high fabrication cost and process complexity.…”

Lead‐Free Double Perovskite Cs2SnX6: Facile Solution Synthesis and Excellent Stability

“…Figure a also exhibits the working principle of the photodetector: the Cs 2 SnI 6 will absorb light and generate electron–hole pairs under illumination. Subsequently, the electron–hole pairs would be separated rapidly and collected by the electrodes under external electrical field respectively . In order to understand this process clearly, we also plotted the energy level diagram with exact conduction band minimum (CBM) and valence band maximum (VBM) values, as shown in Figure S8a in the Supporting Information.…”