Highly efficient light-emitting diodes via self-assembled InP quantum dots
Hui Li, Jingyuan Zhang, Wen Wen, Yuyan Zhao, Hanfei Gao, Bingqiang Ji, Yunjun Wang, Lei Jiang, Yuchen Wu
Abstract
Abstract Heavy-metal-free quantum dot light-emitting diodes (QLEDs) face commercialization challenges due to low efficiency and poor stability. Spin-coated quantum dot films often create charge leakage areas, limiting device performance. Here, we develop an evaporative-driven self-assembly strategy that enables the preparation of uniform and dense InP-based quantum dot films. During device operation, these films effectively suppress performance degradation caused by charge leakage. QLEDs with uniform and dense InP-based quantum dot films achieve high external quantum efficiency (26.6%) and luminance (1.4 × 10 5 cd m −2 ), along with considerable stability (extrapolated T 50 lifetime of 4026 hours at 1000 cd m −2 ). For a 2 × 3 cm 2 InP-based device, the peak external quantum efficiency reaches 21.1%. By combining high-performance QLEDs with lithography technology, we fabricate miniaturized QLEDs with a minimum pixel size of 3 μm, achieving a resolution as high as 5080 pixels per inch and a peak external quantum efficiency of 22.6%.