Impacts of Si-doping on vacancy complex formation and their influences on deep ultraviolet luminescence dynamics in Al x Ga 1− x N films and multiple quantum wells grown by metalorganic vapor phase epitaxy
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2021-12-28 |
| Journal | Japanese Journal of Applied Physics |
| Authors | Shigefusa F. Chichibu, Hideto Miyake, Akira Uedono |
| Institutions | University of Tsukuba, Tohoku University |
| Citations | 8 |
Abstract
Section titled “Abstract”Abstract To find a clue to increase the emission efficiencies of Al x Ga 1− x N-based deep ultraviolet light emitters, the origins and influences on carrier concentration and minority carrier lifetime ( <mml:math xmlns:mml=“http://www.w3.org/1998/Math/MathML” overflow=“scroll”> <mml:msub> <mml:mrow> <mml:mi>τ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant=“normal”>minority</mml:mi> </mml:mrow> </mml:msub> </mml:math> ), which determines the internal quantum efficiency, of midgap recombination centers in c -plane Si-doped Al 0.60 Ga 0.40 N epilayers and Al 0.68 Ga 0.32 N quantum wells (QWs) grown by metalorganic vapor phase epitaxy were studied by temporally and spatially resolved luminescence measurements, making a correlation with the results of positron annihilation measurement. For the Al 0.60 Ga 0.40 N epilayers, <mml:math xmlns:mml=“http://www.w3.org/1998/Math/MathML” overflow=“scroll”> <mml:msub> <mml:mrow> <mml:mi>τ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant=“normal”>minority</mml:mi> </mml:mrow> </mml:msub> </mml:math> decreased as the concentration of cation vacancies (V III ) increased, indicating that V III , most probably decorated with nitrogen vacancies (V N ), V III (V N ) n , are major nonradiative recombination centers (NRCs). For heavily Si-doped Al 0.60 Ga 0.40 N, a generation of electron-compensating complexes (V III -Si III ) is suggested. For the lightly Si-doping regime, <mml:math xmlns:mml=“http://www.w3.org/1998/Math/MathML” overflow=“scroll”> <mml:msub> <mml:mrow> <mml:mi>τ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant=“normal”>minority</mml:mi> </mml:mrow> </mml:msub> </mml:math> of the QW emission was increased by appropriate Si-doping in the wells, which simultaneously increased the terrace width. The importance of wetting conditions is suggested for decreasing the NRC concentration.