This paper introduces the basic kinetic and thermodynamic factors affecting step-bunching instability and derive the one-dimensional(1D) step motion equation based adatom diffusion equation for further analysis.The st...This paper introduces the basic kinetic and thermodynamic factors affecting step-bunching instability and derive the one-dimensional(1D) step motion equation based adatom diffusion equation for further analysis.The step-bunching instability is analyzed for different cases.展开更多
The Si epitaxial films are grown on Si （100） substrates using pure Si2H6 as a gas source using ultrahigh vacuum chemical vapour deposition technology. The values of growth temperature Tg are 650 ℃, 700 ℃, 730 ℃, ...The Si epitaxial films are grown on Si （100） substrates using pure Si2H6 as a gas source using ultrahigh vacuum chemical vapour deposition technology. The values of growth temperature Tg are 650 ℃, 700 ℃, 730 ℃, 750 ℃, and 800 ℃. Growth mode changes from island mode to step-flow mode with Tg increasing from 650 ℃ to 700℃. Rippled surface morphologies are observed at Tg = 700 ℃, 730 ℃, and 800℃, but disappear when Tg = 750℃. A model is presented to explain the formation and the disappearance of the ripples by considering the stability of the step-flow growth.展开更多
AlGaN-based light-emitting diodes(LEDs)on offcut substrates enhance radiative emission via forming carrier localization centers in multiple quantum wells(MQWs).This study introduces the carrier transport barrier conce...AlGaN-based light-emitting diodes(LEDs)on offcut substrates enhance radiative emission via forming carrier localization centers in multiple quantum wells(MQWs).This study introduces the carrier transport barrier concept,accessing its impact on the quantum efficiency of LEDs grown on different offcut sapphire substrates.A significantly enhanced internal quantum efficiency(IQE)of 83.1%is obtained from MQWs on the 1°offcut sapphire,almost twice that of the controlled 0.2°offcut sample.Yet,1°offcut LEDs have higher turn-on voltage and weaker electroluminescence than 0.2°ones.Theoretical calculations demonstrate the existence of a potential barrier on the current path around the step-induced Ga-rich stripes.Ga-rich stripes reduce the turn-on voltage but restrict sufficient driving current,impacting LED performance.展开更多
文摘This paper introduces the basic kinetic and thermodynamic factors affecting step-bunching instability and derive the one-dimensional(1D) step motion equation based adatom diffusion equation for further analysis.The step-bunching instability is analyzed for different cases.
基金supported by the Major State Basic Research Program of China (Grant No. 2007CB613404)the National High Technology Research and Development Program of China (Grant No. 2006AA03Z415)+1 种基金the National Natural Science Foundation of China(Grant Nos. 60676005,61036003,and 60906035)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No. ISCAS2009T01)
文摘The Si epitaxial films are grown on Si （100） substrates using pure Si2H6 as a gas source using ultrahigh vacuum chemical vapour deposition technology. The values of growth temperature Tg are 650 ℃, 700 ℃, 730 ℃, 750 ℃, and 800 ℃. Growth mode changes from island mode to step-flow mode with Tg increasing from 650 ℃ to 700℃. Rippled surface morphologies are observed at Tg = 700 ℃, 730 ℃, and 800℃, but disappear when Tg = 750℃. A model is presented to explain the formation and the disappearance of the ripples by considering the stability of the step-flow growth.
基金supported by the National Natural Science Foundation of China(No.62104233)the Natural Science Foundation of Ningbo(No.2022J298)+1 种基金the Zhejiang Provincial Natural Science Foundation(No.LQ21F040004)the Ningbo Innovation 2025 Major Project(No.2021Z082)。
文摘AlGaN-based light-emitting diodes(LEDs)on offcut substrates enhance radiative emission via forming carrier localization centers in multiple quantum wells(MQWs).This study introduces the carrier transport barrier concept,accessing its impact on the quantum efficiency of LEDs grown on different offcut sapphire substrates.A significantly enhanced internal quantum efficiency(IQE)of 83.1%is obtained from MQWs on the 1°offcut sapphire,almost twice that of the controlled 0.2°offcut sample.Yet,1°offcut LEDs have higher turn-on voltage and weaker electroluminescence than 0.2°ones.Theoretical calculations demonstrate the existence of a potential barrier on the current path around the step-induced Ga-rich stripes.Ga-rich stripes reduce the turn-on voltage but restrict sufficient driving current,impacting LED performance.
