Light‐Emitting Diodes with Cu‐Doped Colloidal Quantum Wells: From Ultrapure Green, Tunable Dual‐Emission to White Light

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 15; no. 38; pp. e1901983 - n/a
• Main Authors: Liu, Baiquan, Sharma, Manoj, Yu, Junhong, Shendre, Sushant, Hettiarachchi, Chathuranga, Sharma, Ashma, Yeltik, Aydan, Wang, Lin, Sun, Handong, Dang, Cuong, Demir, Hilmi Volkan
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-09-2019
• Subjects: colloidal quantum wells; Colloids; Copper; Doping; dual emission; Electroluminescence; Emission; Impurities; impurity doping; Light emitting diodes; nanoplatelets; Nanotechnology; Optoelectronics; Organic light emitting diodes; Quantum wells; White light; nanoplatelets; light-emitting diodes; impurity doping; colloidal quantum wells; dual emission
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201901983

Copper‐doped colloidal quantum wells (Cu‐CQWs) are considered a new class of optoelectronic materials. To date, the electroluminescence (EL) property of Cu‐CQWs has not been revealed. Additionally, it is desirable to achieve ultrapure green, tunable dual‐emission and white light to satisfy the various requirement of display and lighting applications. Herein, light‐emitting diodes (LEDs) based on colloidal Cu‐CQWs are demonstrated. For the 0% Cu‐doped concentration, the LED exhibits Commission Internationale de L'Eclairage 1931 coordinates of (0.103, 0.797) with a narrow EL full‐wavelength at half‐maximum of 12 nm. For the 0.5% Cu‐doped concentration, a dual‐emission LED is realized. Remarkably, the dual emission can be tuned by manipulating the device engineering. Furthermore, at a high doping concentration of 2.4%, a white LED based on CQWs is developed. With the management of doping concentrations, the color tuning (green, dual‐emission to white) is shown. The findings not only show that LEDs with CQWs can exhibit polychromatic emission but also unlock a new direction to develop LEDs by exploiting 2D impurity‐doped CQWs that can be further extended to the application of other impurities (e.g., Mn, Ag).
For the first time, light‐emitting diodes (LEDs) based on Cu‐doped colloidal quantum wells (CQWs) are developed. With 0% Cu‐doped concentration, the “greenest” LED is reported. For the 0.5% Cu‐doped concentration, a dual‐emission LED is realized. The dual emission can be tuned by manipulating the device engineering. At a doping concentration of 2.4%, a white LED based on CQWs is developed.