Spray-pyrolysed thin films open the door for both economic and eco-friendly portable device production. Moreover, the use of earth-abundant elements such as Sn and Cu for the preparation of thin films will considerably reduce the production cost of the device. Here we are reporting a new technique for bandgap tuning of SnS nanomaterial without adding any type of metal as dopant through a vacuum-free chemical spray pyrolysis technique for various opto-electronic applications such as supercapacitors, batteries, and solar cells. Both p-type and n-type SnS thin films were fabricated. Trial studies were performed on the fabrication of heterojunctions using n-SnS and p-c-Si. The reverse saturation current (J0) value obtained for the diode is 1.7 × 10-6 A. The ideality factor (n) is found to be 2.89. The as-prepared SnS thin films have a bandgap ranging from 1.84 eV to 1.45 eV and a maximum optical absorption coefficient of 105 cm−1 in the wavelength range 400–800 nm.