Low‐Temperature Deposition of Layered SnSe2 for Heterojunction Diodes

Abstract Tin diselenide (SnSe 2 ) has been recently investigated as an alternative layered metal dichalcogenide due to its unique electrical and optoelectronics properties. Although there are several reports on the deposition of layered crystalline SnSe 2 films by chemical and physical methods, synthesis methods like pulsed laser deposition (PLD) are not reported. An attractive feature of PLD is that it can be used to grow 2D films over large areas. In this report, a deposition process to grow stoichiometric SnSe 2 on different substrates such as single crystals (Sapphire) and amorphous oxides (SiO 2 and HfO 2 ) is reported. A detailed process flow for the growth of 2D SnSe 2 at temperatures of 300 °C is presented, which is substantially lower than temperatures used in chemical vapor deposition and molecular beam epitaxy. The 2D SnSe 2 films exhibit a mobility of ≈4.0 cm 2 V −1 s −1 , and are successfully used to demonstrate SnSe 2 /p‐Si heterojunction diodes. The diodes show I on / I off ratios of 10 3 –10 4 with a turn on voltage of <0.5 V, and ideality factors of 1.2–1.4, depending on the SnSe 2 film growth conditions.