One-Step Fabrication Method of GaN Films for Internal Quantum Efficiency Enhancement and Their Ultrafast Mechanism Investigation

• DOI: 10.1021/acsami.0c19726
• Publication Date: 2021-02-08T08:33:08Z
• Authors: Feifei Wang; Lan Jiang; Jingya Sun; Changji Pan; Yiling Lian; Jiaxin Sun; Kai Wang; Qingsong Wang; Jiaxing Wang; Yongfeng Lu
• Keywords: PL; X-ray photoelectron spectroscopy; UV-light-emitting diodes; Chemical Sciences not elsewhere classified; Biophysics; 02 engineering and technology; microbump structure formation; time-resolved reflection; application prospect; full-field imaging; One-Step Fabrication Method; phase explosion; IQE; Space Science; XPS; GaN Films; 5.5 times enhancement; Ultrafast Mechanism Investigation; femtosecond lasers; femtosecond laser fluences; bubble nucleation; quantum efficiency; LED; femtosecond laser processing; power semiconductor leap; femtosecond laser fabrication method; 3 times improvement; GaN film; band gap semiconductors; Raman spectroscopy; Internal Quantum Efficiency Enhancement; 0210 nano-technology; Physical Sciences not elsewhere classified; Biotechnology

The third-generation semiconductors are the cornerstone of the power semiconductor leap forward and have attracted much attention because of their excellent properties and wide applications. Meanwhile, femtosecond laser processing as a convenient method further improves the performance of the related devices and expands the application prospect. In this work, an approximate 3 times improvement of the internal quantum efficiency (IQE) and a 5.5 times enhancement of the photoluminescence (PL) intensity were achieved in the GaN film prepared using a one-step femtosecond laser fabrication method. Three types of final micro/nanostructures were found with different femtosecond laser fluences, which could be attributed to the decomposition, melting, bubble nucleation, and phase explosion of GaN. The mechanisms of the microbump structure formation and enhancement of IQE were studied experimentally by the time-resolved reflection pump-probe technique, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Simulations for the laser-GaN interaction have also been performed to ascertain the micro/nanostructure formation principle. These results promote the potential applications of femtosecond lasers on GaN and other wide band gap semiconductors, such as UV-light-emitting diodes (LEDs), photodetectors, and random lasers for use in sensing and full-field imaging.