Self-compensation effect in Si-doped Al_0.55Ga_0.45N layers for deep ultraviolet applications

Abstract

The self-compensation effect in Si-doped Al 0.55 Ga 0.45 N layers was investigated using different SiH 4 /III ratios. The degree of compressive strain changed with SiH 4 flow rate during growth. With a low SiH 4 /III ratio of 2.46 ' 10 %6 , compressive strain was increased in comparison with the un-doped case. However, above this SiH 4 /III ratio, compressive strain decreased from ε xx = %5.07 ' 10 %3 to 4.28 ' 10 %3 when the ratio was increased to 4.1 ' 10 %5 . For higher SiH 4 /III ratios, the compressive strain again increased, which is attributed to the self-compensation effect of Si atoms. A similar tendency was observed in Photo-luminescence (PL) results. While the UV-to-violet ratio (I UV /I VL ) of room-temperature PL remained to be almost constant for SiH 4 /III ratios below 8.2 ' 10 %5 , I UV /I VL decreased rapidly above this value, as a result of self-compensation of Si atoms. These results were in good agreement with the Hall effect measurements.

Low resistivity of highly Si-doped n-type Al0.62Ga0.38N layer by suppressing self-compensation

“…1. [9][10][11][12][13][14][28][29][30][31][32][33][34][35][36] The lowest resistance of n-AlGaN with an AlN mole fraction of 62% was achieved in this study. The lowest resistivity value of the Al 0.62 Ga 0.38 N layer reached 6.6 × 10 −3 Ω cm at the Si concentration of 3.2 × 10 19 cm −3 .…”

“…(Color online) Resistivity values as a function of the AlN mole fraction for n-AlGaN layers. The data reported from other studies are indicated as open symbols,[9][10][11][12][13][14][28][29][30][31][32][33][34][35][36] while our results are shown as red closed symbols.…”

Efficiency improvement of AlGaN-based deep-ultraviolet light-emitting diodes and their virus inactivation application

“…Figure 3 summarizes the AlN mole fraction dependence of the resistivity of n-type AlGaN layers, showing our results as well as those reported previously. [19][20][21][22][23][24][35][36][37][38][39][40][41][42][43] We have reported the lowest resistivity (6.6 × 10 −3 Ω cm) of n-type AlGaN layer with x ∼ 0.62 at [Si] = 3.2 × 10 19 cm −3 . 30) We confirmed that this resistivity value allowed no visible resistance loss at the ntype AlGaN contact layer in the UV-LEDs.…”

“…3. (Color online) Reported resistivity values [19][20][21][22][23][24][35][36][37][38][39][40][41][42][43] for Si-doped Al x Ga 1−x N layers with various AlN mole fractions. We obtained one of the lowest resistivity values at x ∼ 0.62 by optimizing the growth conditions.…”

Deep-Ultraviolet AlGaN/AlN Core-Shell Multiple Quantum Wells on AlN Nanorods via Lithography-Free Method

“…Aluminum nitride (AlN) based devices operating in the deep ultraviolet (UVC) regime (200–280 nm) have attracted considerable attention owing to their wide range of potential applications such as medical therapy, UV curing, biochemical sensing, water or air purification, and disinfection 1 – 3 . However, AlN based UVC devices still suffer from low quantum efficiency and output power.…”