Green Solvent Selection for All Solution-Processed Inverted Quantum Dot Light Emitting Diode

Quantum-dot light-emitting diodes (QD-LEDs) have gained attention as potential display technologies. However, the solvents used to dissolve a polymeric hole transport layer (HTL) are hazardous to both humans and the environment. Additionally, intermixing the HTL and QD layers presents a significant challenge when fabricating inverted QD-LEDs. Here, a green solvent selection procedure to achieve good device performance and environmental safety in QD-LEDs is established. This procedure utilizes Hansen solubility parameters and surface roughness to identify a set of solvents that do not lower the device performance by avoiding interlayer mixing or a rough interface. The CHEM21 solvent selection guide is used to screen for environmentally hazardous solvents. Finally, cyclopentanone (CPO) is selected as the optimal HTL solvent from among 16 candidates. Using CPO improves the maximum luminescence by approximate to 1.6 times and the maximum current efficiency by approximate to 12.6 times, compared to that of conventional devices using hazardous chlorobenzene. Solvent selection is critical for the fabrication of green and high-performance inverted QD-LEDs, particularly for large display panels that require n-type oxide thin-film transistors. A green solvent selection procedure is introduced to achieve both good device performance and environmental safety in solution-processed quantum-dot light-emitting diodes (QD-LEDs). Hansen solubility parameters, surface roughness analysis, and the CHEM21 solvent selection guide are utilized, and cyclopentanone (CPO) is finally selected. The inverted QD-LED using CPO exhibits 12.6 times higher maximum current efficiency. image