title: A novel wavelength-adjusting method in InGaN-based light-emitting diodes.
abstract: The pursuit of high internal quantum efficiency (IQE) for green emission spectral regime is referred as "green gap" challenge. Now researchers place their hope on the InGaN-based materials to develop high-brightness green light-emitting diodes. However, IQE drops fast when emission wavelength of InGaN LED increases by changing growth temperature or well thickness. In this paper, a new wavelength-adjusting method is proposed and the optical properties of LED are investigated. By additional process of indium pre-deposition before InGaN well layer growth, the indium distribution along growth direction becomes more uniform, which leads to the increase of average indium content in InGaN well layer and results in a redshift of peak-wavelength. We also find that the IQE of LED with indium pre-deposition increases with the wavelength redshift. Such dependence is opposite to the IQE-wavelength behavior in conventional InGaN LEDs. The relations among the IQE, wavelength and the indium pre-deposition process are discussed.
authors.affiliation: Key Laboratory for Renewable Energy, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Deng
authors.affiliation: Key Laboratory for Renewable Energy, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Key Laboratory for Renewable Energy, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Ziguang
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Key Laboratory for Renewable Energy, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Wenxin
authors.initials: W
authors.lastname: Wang
authors.affiliation: Beijing Key Laboratory for New Energy Materials and Devices, Beijing 100190, China.
authors.forename: Haiqiang
authors.initials: H
authors.lastname: Jia
authors.affiliation: Beijing Key Laboratory for New Energy Materials and Devices, Beijing 100190, China.
authors.forename: Junming
authors.initials: J
authors.lastname: Zhou
authors.affiliation: 1] Key Laboratory for Renewable Energy, Chinese Academy of Sciences, Beijing 100190, China [2] Beijing Key Laboratory for New Energy Materials and Devices, Beijing 100190, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Chen