Rapid Photonic Processing of High-Electron-Mobility PbS Colloidal Quantum Dot Transistors

• Published in: ACS applied materials & interfaces Vol. 12; no. 28; pp. 31591 - 31600
• Main Authors: Nugraha, Mohamad I, Yarali, Emre, Firdaus, Yuliar, Lin, Yuanbao, El-Labban, Abdulrahman, Gedda, Murali, Lidorikis, Elefterios, Yengel, Emre, Faber, Hendrik, Anthopoulos, Thomas D
• Format: Journal Article
• Language: English
• Published: American Chemical Society 15.07.2020
• Subjects: annealing; films (materials); Functional Inorganic Materials and Devices; lead; manufacturing; photons; polymers; quantum dots; silica; sulfides; transistors; xenon; solution-processed semiconductors; colloidal quantum dots; flash lamp annealing; large-area electronics; thin-film transistors
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.0c06306

Recent advances in solution-processable semiconducting colloidal quantum dots (CQDs) have enabled their use in a range of (opto)­electronic devices. In most of these studies, device fabrication relied almost exclusively on thermal annealing to remove organic residues and enhance inter-CQD electronic coupling. Despite its widespread use, however, thermal annealing is a lengthy process, while its effectiveness to eliminate organic residues remains limited. Here, we exploit the use of xenon flash lamp sintering to post-treat solution-deposited layers of lead sulfide (PbS) CQDs and their application in n-channel thin-film transistors (TFTs). The process is simple, fast, and highly scalable and allows for efficient removal of organic residues while preserving both quantum confinement and high channel current modulation. Bottom-gate, top-contact PbS CQD TFTs incorporating SiO2 as the gate dielectric exhibit a maximum electron mobility of 0.2 cm2 V–1 s–1, a value higher than that of control transistors (≈10–2 cm2 V–1 s–1) processed via thermal annealing for 30 min at 120 °C. Replacing SiO2 with a polymeric dielectric improves the transistor’s channel interface, leading to a significant increase in electron mobility to 3.7 cm2 V–1 s–1. The present work highlights the potential of flash lamp annealing as a promising method for the rapid manufacture of PbS CQD-based (opto)­electronic devices and circuits.