Processing Poly(3‐Hexylthiophene) Interlayer with Nonhalogenated Solvents for High‐Performance and Low‐Cost Quantum Dot Solar Cells

Abstract

Hybrid solar cells with organic semiconductors and quantum dots (QDs) have witnessed great advance in the past few years. Nevertheless, the great majority of organic and QD hybrid solar cells generally employ halogenated solvents for the processing of organic hole‐transporting interlayers. Herein, the impact of solvents on the organic semiconductor material for hybird solar cells is systematically explored. The o‐xylene‐processed polythiophene delivers a champion photovoltaic performance of 8.7%, which is the record value for QD and poly(3‐hexylthiophene) (P3HT) hybrid solar cells. The morphology results reveal that P3HT films processed with o‐XY present the moderate morphology and characteristic length scales, enabling the high photovoltaic performance. Moreover, the relationships between solvents, molecular stacking, film morphology, and photovoltaic performance are built to offer the guideline of solvents screening for these hybrid solar cells. Moreover, the great superiority of nonhalogenated solvents in fabricating high‐performance optoelectronic devices with low hazards is demonstrated.

Organic and quantum dot hybrid photodetectors: towards full-band and fast detection

“…50 Such fast response speed may be attributed to the low exciton binding energy, high carrier mobility and favorable device structure, which can enable fast exciton dissociation, carrier transport and extraction for photodetectors even without bias. 94 In contrast, the high exciton binding energy and low carrier mobility may place great restrictions on the fast-response photodetectors. [95][96][97] Therefore, it is highly desirable to address the challenge via introducing versatile QD materials into organic photodetectors.…”

Constructing High‐Performance Solar Cells and Photodetectors with a Doping‐Free Polythiophene Hole Transport Material

“…P3PT presented a free exciton bandwidth of ≈159 meV, which was lower than that of P3HT (≈210 meV), indicating the reduced stack order and aggregation of polythiophenes. According to our recent work, [ 63–65 ] the lower molecular aggregation can form the favorable morphology for efficient carrier transport in QD/polythiophene heterojunctions.…”

Toward efficient hybrid solar cells comprising quantum dots and organic materials: progress, strategies, and perspectives

“…163,164 Our recent report demonstrated that nonhalogenated solvent processing can boost the PCE of PbS QD/P3HT hybrid solar cells up to 8.7%, setting a new record for this type of hybrid solar cells. 165 Further investigations have conrmed that the mismatch of energy landscape between QDs and P3HT emerged as the major roadblock in performance improvement. Polymers with low energy level indeed delive faster hole transport, leading to the further performance increase with PCEs of ∼10% for PTB7, 166 ∼10.3% for PTB7-Th, 167 11.2% for PBDB-TF, 168 and 11.5% for PBDTTPD-HT.…”