Abstract Metal halide perovskite films were prepared using two different deposition techniques, namely one-step spin coating (OSSC) and two-step spin coating (TSSC) and used as the active layer in perovskite photodetectors (PDs). Surface morphology studies revealed that perovskite thin films grown by OSSC exhibited large density of pin holes and non-uniform surface coverage. While, the film produced by TSSC shows full surface coverage with lesser pin holes. By comparing the device performance of the photodetectors based on OSSC and TSSC deposited films, we found that TSSC deposited film based PD demonstrated a significant enhancement in the performance (Responsivity of 1.05 A/W and detectivity of 1.27 × 1011 Jones @ −1 V) in comparison to the PD based on OSSC deposited films (Responsivity of 0.019 A/W and a detectivity of 1.77 × 109 Jones @ −1 V), which can be attributed to the higher absorbance, lesser trap density, narrower trap width, larger carrier mobility and lower leakage current, arising from better surface morphology and crystallinity of TSSC deposited films. Impedance analysis of PD prepared from TSSC film showed a relatively large charge recombination resistance and a long lifetime than PD fabricated from OSSC film, signifying less charge recombination events, which is in consistent with the high performance achieved with the TSSC film based PD.

中文翻译：

---

通过两步旋涂方法制造的钙钛矿光电探测器的性能增强

摘要 采用一步旋涂 (OSSC) 和两步旋涂 (TSSC) 两种不同的沉积技术制备金属卤化物钙钛矿薄膜，并将其用作钙钛矿光电探测器 (PD) 的活性层。表面形态研究表明，OSSC 生长的钙钛矿薄膜表现出大密度的针孔和不均匀的表面覆盖。同时，TSSC 生产的薄膜显示出完整的表面覆盖，针孔较少。通过比较基于 OSSC 和 TSSC 沉积膜的光电探测器的器件性能，我们发现基于 TSSC 沉积膜的 PD 表现出显着的性能提升（响应率为 1.05 A/W，探测率为 1.27 × 1011 Jones @ -1 V）与基于 OSSC 沉积膜的 PD 相比（响应率为 0.019 A/W，探测率为 1.77 × 109 Jones @ -1 V），这可以归因于更高的吸光度、更小的陷阱密度、更窄的陷阱宽度、更大的载流子迁移率和更低的漏电流，这是由于 TSSC 沉积膜的更好的表面形貌和结晶度引起的。由 TSSC 薄膜制备的 PD 的阻抗分析表明，与由 OSSC 薄膜制备的 PD 相比，具有相对较大的电荷复合电阻和较长的寿命，表明电荷复合事件较少，这与基于 TSSC 薄膜的 PD 实现的高性能一致。