Solvent free spray coated n type PEDOT PSS thin film for high performance homojunction diode

Pristine PEDOT: PSS is a p-type material with salient features. However, studies have revealed that the electrical property of pristine PEDOT: PSS can be switched to n-type by solvent treatment. Notwithstanding that this method is simple, it performs inconsistently and primarily affects the samples' surfaces due to the migration of the solvent molecules into the polymer network. These solvents are also hazardous and unfavourable to the environment. In this work, we report solvent-free switching electrical characteristics of pristine PEDOT: PSS to n-type using a spray coating technique. The obtained n-PEDOT: PSS exhibits excellent optical and electrical characteristics. In addition, high Seebeck coefficient of - 1320.06 ± 38.42 µVK^-1 and power factor of 4.32 ± 0.25 µWm^-1K^-2 were found. The obtained n-PEDOT: PSS was used in the fabrication of a homojunction diode. The I-V curve showed rectification characteristics with rectification ratio and barrier height of 17.2 and 0.047 eV, respectively, which is one of the best reported values in the literature for all PEDOT: PSS-based diode.