Efficiency Improvement of Deep‐Ultraviolet Light Emitting Diodes with Gradient Electron Blocking Layers. Issue 10 (24th November 2017)

• Record Type: Journal Article
• Authors: So, Byeongchan; Kim, Jinwan; Shin, Eunyoung; Kwak, Taemyung; Kim, Taeyoung; Nam, Okhyun
• Other Names: Scholz Ferdinand guestEditor.; Schwarz Ulrich guestEditor.; Vescan Andrei guestEditor.; Wernicke Tim guestEditor.
• Is Part Of: Physica status solidi. Volume 215:Issue 10(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-11-24
• Subjects: deep‐ultraviolet light emitting diodes -- electron blocking layers -- metal‐organic chemical vapor deposition -- MOCVD; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201700677
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : In this paper, a gradient electron blocking layer (GEBL) is introduced to improve efficiency of deep‐ultraviolet light‐emitting diodes (DUV‐LEDs). Various structures of DUV‐LEDs are simulated to determine the energy band diagram variation and carrier injection mechanism resulting from the insertion of the GEBL. The simulation results show the improved electron and hole transport behavior in AlGaN multi quantum wells (MQWs). Especially, the injection efficiency of holes is improved with the increasing number of GEBL steps, which lead to the enhancement of internal quantum efficiency (IQE). The DUV‐LED structures with GEBL are grown in a high‐temperature metal‐organic chemical vapor deposition (HT‐MOCVD) system. Electroluminescence (EL) spectra show that the emission intensity at a wavelength of 280 nm from a DUV‐LED with a 12‐steps EBL is about 2.3 times that from a DUV‐LED with a single EBL. Abstract : To improve the performance of deep‐UV light emitting diodes (DUV‐LEDs), the gradient electron blocking layers (GEBLs) are introduced. DUV‐LED structures with different GEBLs are grown by high‐temperature MOCVD. The electroluminescence intensity of the LED with 12‐step EBL is approximately 2.3 times that of LED with single EBL at 280 nm. Also, all simulation data support the effect of a GEBL on DUV‐LEDs.