P-type Cu-Sn-I thin films with different Sn contents (CSn) were fabricated in air via a simple and low-cost spin-coating method. Sn additive facilitates the amorphization of CuI, and a complete amorphous phase of Cu-Sn-I film is achieved at CSn =15%. With increasing CSn, the optical bandgap increases and refractive index decreases, probably due to the influence of Sn-additive on both the electronic structure and phase state of the films. The air-processed Sn-free CuI films show p-type conduction with hole mobility and a concentration of 17.3 cm2/V−1 s−1 and 1.1 × 1019 cm−3, and an increasing trend of resistivity is observed along with a large drop in hole concentration during the Sn-inspired amorphization process. Moreover, transparent Cu-Sn-I/IGZO p–n junctions were constructed, exhibiting the optimum rectifying characteristic at CSn = 15% with a forward-to-reverse ratio of 6.2 × 103.

High-field-effect-mobility InSnZnO thin-film transistors (TFTs) are prepared through Al-induced microstructure regularization (AIMR) at an annealing temperature lower to 400 °C. Spherical crystalline particles are distributed throughout the back channel near the Al layer, while an amorphous phase still represents the front channel but with enhanced microstructure ordering. Especially, the packing density is distinctly increased, and oxygen vacancies are largely reduced. The optimized TFT exhibits excellent performance with a steep sub-threshold swing of 0.18 V/dec, a high on/off current ratio of 2.5 × 108, a threshold voltage of −0.21 V, and a small threshold voltage shift of −0.24 V under negative bias stress (−20 V, 3600 s), especially a remarkable field-effect mobility boosted to 53.2 cm2/V s compared to 19.1 cm2/V s for the TFT without the Al layer. After Al removal, the TFT performance shows no obvious degradation, implying good compatibility of the AIMR technique to the current device process.