Low-temperature formation of GeSn nanocrystallite thin films by sputtering Ge on self-assembled Sn nanodots on SiO2/Si substrate

A simple method to form GeSn nanocrystallite thin films with high Sn composition at low temperature by sputtering Ge on self-assembled Sn nanodots is proposed. During the sputtering process, Ge atoms diffuse into Sn nanodots and then nanocrystalline GeSn freezes out as temperature is above 150 °C. GeSn nanocrystallite thin films with high Sn composition of 27.3% are achieved at 150 °C and Sn composition decreases gradually with elevation of temperature. The hole mobility of the GeSn nanocrystallite thin film of 14.0 cm2V−1s−1 is achieved with the process temperature of less than 275 °C, which is suitable for flexible electronics.