Substrate temperature dependent nucleation and growth study of pulsed laser deposited MoS₂ thin films

MoS₂ films have been deposited on SiO₂/Si substrate by applying 200 numbers of laser pulses at a laser fluence of 2.2 J/cm².The substrate temperature effects on film growth and on its structural properties have been studied at 300 °C, 400 °C, 500 °C and 600 °C. Among the two Raman vibration modes, A_1g Peak position remains unchanged while E_2g1 peak blue shifted significantly at higher deposition temperature. The root mean square roughness and amorphous nature of films going to decreases with increases the substrate temperature. The film deposited at 600 °C showed Rms roughness of 0.33 nm, while at the temperature 300 °C the roughness of the film was quite high at 3.95 nm. Film deposited at 300 °C followed the Volmer-Weber nucleation and growth model while stranski- Krastinov model was followed by films deposited at higher substrate temperatures. (author)