Effects of the number of wells on the performance of green InGaN/GaN LEDs with V-shape pits grown on Si substrates. (February 2018)

• Record Type: Journal Article
• Authors: Wu, Qingfeng; Zhang, Jianli; Mo, Chunlan; Wang, Xiaolan; Quan, Zhijue; Wu, Xiaoming; Pan, Shuan; Wang, Guangxu; Liu, Junlin; Jiang, Fengyi
• Is Part Of: Superlattices and microstructures. Volume 114(2018)
• Page Start: 89
• Page End: 96
• Publication Date: 2018-02
• Subjects: Green light emitting diodes -- The number of wells -- V-shape pits -- Interface roughness; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2017.12.012
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: The effect of the number of wells on quantum efficiency and forward voltage of vertical green InGaN/GaN multiple quantum wells (MQWs) light-emitting diodes (LEDs) grown on Si substrate has been experimentally investigated. We have prepared three LED samples with 3, 5 and 7 wells. Electroluminescence measurement shows that the LED with 5 wells has the highest external quantum efficiency (EQE) and the lowest forward voltage. It is observed that V-shaped pits grow up in size and density with an increase in quantum well number by means of scan electron microscope. Due to more hole injection via V-shaped pits, a larger area ratio of pits as a result of more number of wells would bring a lower forward voltage and a higher EQE. However, besides the increasing series resistance would bring a higher forward voltage, the interface of MQWs would become rougher and deteriorate the emission efficiency when increasing the wells number. Highlights: V-shaped pits grow up in size and density with an increase in quantum well number. A larger area ratio of pits would bring a lower forward voltage. The interface of MQWs would become rougher with increase of wells number.