Controlled doping and growth of SnSe thin films via pulsed laser deposition

SnSe has received significant attention due to its exceptional optoelectronic and thermoelectric properties, making it a promising candidate for energy conversion applications. To exploit its potential for photo-thermoelectric applications, it is essential to prepare high-quality SnSe single-crystal films and investigate their intrinsic properties and local structure. In this work, pure and Na, Cu doped SnSe films were prepared via pulsed laser deposition (PLD). Orthorhombic SnSe films were successfully deposited along the [100] direction on SrTiO₃ substrates. Our results show that the growth mode of SnSe films transitions from island-by-layer to 3D island growth as the film thickness increases. Notably, SnSe doped with Na and Cu restores a flatter surface even at larger thicknesses, and the current output of the Na and Cu doped SnSe film under optical and thermal excitations exhibited a significant improvement compared to the individual photo-induced and thermal-induced, as well as the sum of both, highlighting its potential for integrated photoelectric-thermoelectric applications.