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Controlling perovskite crystal growth plays an important role in improving perovskite solar cell performance. The low pressure assisted solution processing (LPSP) method was developed to improve crystalline quality of thin films and conversion efficiency of devices. It enabled to control removal speed of solvent mixtures unanimously kept in low pressure environment below 1000 Pa. Compared to common pressure condition, it produced highly (1 1 0) oriented CH3NH3PbI3−xClx thin films and devices possessed excellent PCE above 17% by LPSP. So it is effective method to enlarge grain size, optimize roughness of interface and improve carrier mobility.

Polycrystalline α-phase mercuric iodide (α-HgI2) film arrays have been prepared on ITO-coated glass substrates by hot-wall physical vapor deposition (HWPVD) method with the mask of 4 × 4 arrays. Film arrays are prepared based on one-step mask method. It is found that there exist differences between central parts and marginal parts of arrays in two aspects including surface morphology and electrical performance. The size distribution of grains in the edge is not uniform and grain boundaries are not clear, but the size distribution in the centre is consistent in morphology. In the aspect of electrical performance, the lowest leakage current of marginal parts and central parts is 4.95 × 10−8 A and 1.01 × 10−8 A respectively. The phenomenon of fringe effect demonstrates that the former is five times as large as the latter. Polishing method is also applied in order to decrease fringe effect of α-HgI2 film arrays. Signal-noise ratios (SNR) of devices are investigated at room temperature irradiated by 5.5 MeV 241Am source.