Pro-environment Cu2O facilitate stable low-wastage ultraviolet p-CuxO/ n-GaN LEDs with virtual electron blocking nanolayer

Light-emitting diodes (LEDs), which convert electricity to light, are widely used in modern society. Herein singlephase Cu2O and mixed-phase CuxO (x = 1, 4/3, 2) films are fabricated on n-GaN to construct p-Cu2O/n-GaN and p-CuxO/n-GaN LEDs, respectively. The application of Cu2O in LEDs is achieved for the first time. Discovering that the p-Cu2O/n-GaN diode hovers a rectification ratio at 95 and a near-ideal leakage current (2.0 x 10-11 A). The near band edge (NBE) emission is located at 372 nm, and the energy proportion of ultraviolet radiation (EPUV, <400 nm) rapidly and steadily stays at 80 % above 3 mW. Under the same injection power (35 mW), the luminous intensity of p-Cu2O/n-GaN is nearly 90 times than that of p-CuxO/n-GaN. Surprisingly marvelous that the energy band structure of Cu2O is equivalent to a virtual electron blocking layer (EBL) in GaN-based LEDs to optimize UV emission performance. Finally, uncased LED chips suffered high temperatures and the constant current aging process. The p-Cu2O/n-GaN LED exhibits a satisfying thermal stability with the optimum working temperature at 70 ~ 100 C. The luminous intensity decays 25.1 % after operating at room temperature (RT) for 3600 s, less than half of the p-CuxO/n-GaN LED, further reveal an exceptional practical application potential.

Automated summary

This study demonstrates the application of Cu2O in LEDs for the first time, showing that the p-Cu2O/n-GaN diode has a high rectification ratio and near-ideal leakage current. The energy band structure of Cu2O optimizes the UV emission performance, resulting in a luminous intensity of p-Cu2O/n-GaN that is 90 times higher than that of p-CuxO/n-GaN. Additionally, the p-Cu2O/n-GaN LED exhibits satisfactory thermal stability at high temperatures, indicating its potential for practical applications.