Thermal annealing is used as a post-deposition processing method for the formation of solid-state organic-inorganic perovskite film of required phase by removing the remnant solvent in as coated film. In the present work, we have studied temperature, time and the application of giving a temperature step for thermal-annealing process. To provide temperature step heating treatment was given to the spin coated film in two consecutive steps; initially heating at lower temperature followed by at 100 °C for 30 min. We show that initial lower temperature annealing step improves crystallite size by retarding crystalline growth due to slower solvent evaporation and obtain improved absorption, phase, surface coverage and mobility. However, if this lower temperature step is not sufficient to step up the formation of desired phase, the second step of higher temperature annealing is also not able to form perovskite phase. This study is supported by studies like UV–visible absorption spectroscopy, Raman spectroscopy, X-ray diffraction, scanning electron microscopy, SCLC measurements etc.

热退火作为沉积后处理方法，通过去除涂层薄膜中的残留溶剂，形成所需相的固态有机-无机钙钛矿薄膜。在目前的工作中，我们研究了热退火工艺的温度、时间和给出温度步长的应用。为了提供温度阶梯加热处理，在两个连续的步骤中对旋涂薄膜进行了加热处理；最初在较低温度下加热，然后在 100 °C 下加热 30 分钟。我们表明，由于较慢的溶剂蒸发，初始低温退火步骤通过延迟晶体生长来改善微晶尺寸，并获得改善的吸收、相、表面覆盖和迁移率。然而，如果这个较低的温度步骤不足以加速所需相的形成，第二步高温退火也不能形成钙钛矿相。这项研究得到了紫外-可见吸收光谱、拉曼光谱、X 射线衍射、扫描电子显微镜、SCLC 测量等研究的支持。