Recent Progress on Quantum Dot Patterning Technologies for Commercialization of QD-LEDs: Current Status, Future Prospects, and Exploratory Approaches.

Colloidal quantum dots (QDs) are widely regarded as advanced emissive materials with significant potential for display applications owing to their excellent optical properties such as high color purity, near-unity photoluminescence quantum yield, and size-tunable emission color. Building upon these attractive attributes, QDs have successfully garnered attention in the display market as down-conversion luminophores and now venturing into the realm of self-emissive displays, exemplified by QD light-emitting diodes (QD-LEDs). However, despite these advancements, there remains a relatively limited body of research on QD patterning technologies, which are crucial prerequisites for the successful commercialization of QD-LEDs. Thus, in this review, an overview of the current status and prospects of QD patterning technologies to accelerate the commercialization of QD-LEDs is provided. Within this review, a comprehensive investigation of three prevailing patterning methods: optical lithography, transfer printing, and inkjet printing are conducted. Furthermore, several exploratory QD patterning techniques that offer distinct advantages are introduced. This study not only paves the way for successful commercialization but also extends the potential application of QD-LEDs into uncharted frontiers.

Effect of Variations in the Alkyl Chain Lengths of Self-Assembled Monolayers on the Crystalline-Phase-Mediated Electrical Performance of Organic Field-Effect Transistors.

Self-assembled monolayers (SAMs) of organic molecules are frequently employed to improve the electrical performance of organic field-effect transistors (OFETs). However, the relationship between SAM properties and OFET performance has not been fully explored, leading to an incomplete understanding of the system. This study investigates the effect of the SAM alkyl chain length on the crystalline phase of pentacene films and OFET performance. Two types of SAMs-with alkyl chain lengths of 10 (decyltrichlorosilane, DTS) and 22 (docosyltrichlorosilane, DCTS)-were examined, and variations in the performance of pentacene-based OFETs with the nature of the SAM treatment were observed. Despite the similar surface morphologies of the pentacene films, field-effect mobility in the DCTS-treated OFET was twice that in the DTS-treated OFET. To find the reason underlying the dependence of the OFET's electrical performance on the SAM alkyl chain length, X-ray diffraction measurements were conducted, followed by a phase analysis of the pentacene films. Bulk and thin-film phases were observed to coexist in the pentacene film grown on DTS, indicating several structural defects in the film; this can help explain the dependence of the OFET electrical performance on the SAM alkyl chain length, mediated by the different crystalline phases of pentacene.