Recent advances in poly(3,4-ethylenedioxyselenophene) and related polymers

Conjugated polythiophene based materials have gained significant interest for organic electronic applications owing to their excellent optical and electrical properties, and their stability in the doped state. The potential use of these polymers has recently created enormous interest in other group 16 element based polyheterocycles, namely, Se based polyselenophene, which have not been explored much despite being known for years. Indeed, the past few years have seen the rapid development of polyselenophene based materials due to their advantageous features, such as narrow band gaps, low redox potentials, higher doping levels, and better charge transport properties compared to thiophene analogues. Poly(3,4-ethylenedioxyselenophene) (PEDOS), the Se analogue of the most successful organic electronic material poly(3,4-ethylenedioxythiophene) (PEDOT), has shown very promising optoelectronic and redox properties, including electrochromism, fast switching between redox states, and high conductivity. In this account, we summarize the key developments in the synthesis, structural characterization, material properties, computational studies, and applications of PEDOS and related polymers during the past five years. The review also throws light on structure-property relationships, such as optical spectra, band gaps, electrochemical, electrochromic, capacitive, photothermal, and thermoelectric properties. A thorough understanding of the electronic and structural properties would contribute to the design and synthesis of novel materials for applications in electrochromic, organic photovoltaic, bioimaging, photothermal, thermoelectric, invisible NIR sensing, and charge storage devices.