Recent Advances in Selenophene-Based Materials for Organic Solar Cells

Abstract

Due to the low cost, light weight, semitransparency, good flexibility, and large manufacturing area of organic solar cells (OSCs), OSCs have the opportunity to become the next generation of solar cells in some specific applications. So far, the efficiency of the OSC device has been improved by more than 20%. The optical band gap between the lowest unoccupied molecular orbital (LUMO) level and the highest occupied molecular orbital (HOMO) level is an important factor affecting the performance of the device. Selenophene, a derivative of aromatic pentacyclic thiophene, is easy to polarize, its LUMO energy level is very low, and hence the optical band gap can be reduced. In addition, the selenium atoms in selenophene and other oxygen atoms or sulfur atoms can form an intermolecular interaction, so as to improve the stacking order of the active layer blend film and improve the carrier transport efficiency. This paper introduces the organic solar active layer materials containing selenium benzene in recent years, which can be simply divided into donor materials and acceptor materials. Replacing sulfur atoms with selenium atoms in these materials can effectively reduce the corresponding optical band gap of materials, improve the mutual solubility of donor recipient materials, and ultimately improve the device efficiency. Therefore, the sulfur in thiophene can be completely replaced by selenium or oxygen of the same family, which can be used in the active layer materials of organic solar cells. This article mainly describes the application of selenium instead of sulfur in OSCs.

Selenium volatilization in plants, microalgae, and microorganisms

“…It can be doped into optical materials to improve their stability and carrier mobility [ 13 ]. In photovoltaic cells, Se can serve as a key material to enhance the conversion efficiency of solar energy into electricity [ 14 ]. In the electronic field, Se is used in the manufacturing of rectifiers, Se batteries, and other electronic devices [ 15 , 16 ].…”

Recent Advances in Selenium‐Containing Non‐fullerene Acceptors for High‐Performance Organic Solar Cells

“…The good planarity and strong crystallinity make selenophene-based fused rings to be a star building block. [31,32] Therefore, the design rules of various selenium-containing materials including ITIC and Y6based fused ring small-molecule acceptors, Y6-based polymer acceptors and non-fused ring small molecule acceptors are highlighted in this review. In addition, we have specifically summarized the location of selenium substitution and its effect on the molecular stacking, carrier mobility, optical bandgap (E g ) and film morphology to comprehensively understand the structure-performance relationship.…”

“…NFAs in efficient OSCs generally required the high‐lying lowest unoccupied molecular orbital (LUMO), good planarity, complementary absorption with donor, etc. The good planarity and strong crystallinity make selenophene‐based fused rings to be a star building block [31,32] . Therefore, the design rules of various selenium‐containing materials including ITIC and Y6‐based fused ring small‐molecule acceptors, Y6‐based polymer acceptors and non‐fused ring small molecule acceptors are highlighted in this review.…”