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H X Jiang - One of the best experts on this subject based on the ideXlab platform.
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acceptor Bound Exciton transition in mg doped aln epilayer
Applied Physics Letters, 2004Co-Authors: Neeraj Nepal, J Y Lin, M L Nakarmi, K B Nam, H X JiangAbstract:Mg-doped AlN epilayers grown by metalorganic chemical-vapor deposition have been studied by deep ultraviolet time-resolved photoluminescence (PL) spectroscopy. A PL emission line at 6.02eV has been observed at 10K in Mg-doped AlN, which is about 40meV below the free-Exciton transition in undoped AlN epilayer. Temperature dependence of the PL intensity of this emission line also reveals a binding energy of 40meV. This transition line is believed to be due to the recombination of an Exciton Bound to neutral Mg acceptor (I1) with a binding energy of Ebx=40meV. This value is also about 10% of the energy level of Mg impurity in AlN satisfying Haynes’ rule. The recombination lifetime of the I1 transition in Mg-doped AlN has been measured to be 130ps, which is close to the expected value. The larger Ebx of the acceptor-Bound Exciton in AlN than that in GaN is due to large effective masses of the electrons and holes, as well as the energy level of Mg impurity.
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time resolved photoluminescence studies of an ionized donor Bound Exciton in gan
Applied Physics Letters, 1999Co-Authors: R A Mair, J Y Lin, S K Duan, H X JiangAbstract:Time-resolved photoluminescence (PL) spectroscopy has been used to study the radiative recombination of Excitons Bound to ionized donors in GaN doped with both Mg and Si at concentrations of 5×1018/cm3 and 1.5×1017/cm3, respectively. Low temperature (T∼10K) time-resolved, as well as integrated PL spectra, identify an ionized donor-Bound (Si) Exciton peak (D+X) approximately 11.5 meV below and a neutral acceptor-Bound Exciton (A0X) 20.5 meV below the free Exciton peak. Rapid decay of the free Exciton emission (⩽20 ps) implies that Excitons are quickly captured by acceptors and ionized donors. We find the (A0X) emission lifetime is consistent with previous measurements for GaN:Mg epilayers, while the (D+X) lifetime of 160 ps is longer than that of the well studied neutral donor-Bound Exciton (D0X). The measured (D+X) lifetime, in comparison with (D0X) and (A0X), suggests that the state is stable at low temperature.
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acceptor Bound Exciton recombination dynamics in p type gan
Applied Physics Letters, 1995Co-Authors: M Smith, Guangde Chen, J Y Lin, H X Jiang, Asif M Khan, C J SunAbstract:Dynamics of the neutral‐acceptor‐Bound Exciton transition (the I1 line) in a Mg doped p‐type GaN epitaxial layer grown by metalorganic chemical vapor deposition (MOCVD) have been studied by time‐resolved photoluminescence emission spectroscopy. Two emission lines in the I1 transition region have been resolved in the time‐resolved spectra, possibly due to the existence of two energy states of the Mg impurities after postgrowth thermal annealing. The recombination lifetimes of the acceptor‐Bound Exciton transition have been measured under different conditions including temperature, excitation intensity, and emission energy. From these measurements, a value of about 450 ps for the radiative recombination lifetime has been obtained, which is an important physical quantity for optoelectronic device applications based on GaN.
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neutral donor Bound Exciton recombination dynamics in gan grown by metalorganic chemical vapor deposition
Applied Physics Letters, 1995Co-Authors: M Smith, Guangde Chen, J Y Lin, H X Jiang, Asif M Khan, C J SunAbstract:Neutral‐donor‐Bound Exciton recombination (I2) dynamics have been studied by photoluminescence in an unintentionally doped n‐type GaN epitaxial layer grown by metalorganic chemical vapor deposition. The luminescence emission line shape, peak position, and intensity as functions of temperature have been measured. In particular, time‐resolved emission spectroscopy has been employed to study the dynamic processes of the Bound Exciton recombination, from which the temperature and the emission energy dependencies of the recombination lifetime of this transition have been obtained.
Hiroshi Kamimura - One of the best experts on this subject based on the ideXlab platform.
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photoluminescence from Bound Exciton states in gap alp short period superlattices in a strong magnetic field
Solid State Communications, 1999Co-Authors: Yuka Kobayashi, K. Kouzu, Hiroshi KamimuraAbstract:Abstract In (GaP) n (AlP) n superlattices the photoluminescence (PL) intensity decreases with increasing magnetic field in the strong field regime in the Faraday configuration. The origin of this unusual behavior of photoluminescence is discussed. In this article we show that a Bound Exciton trapped at a defect at the interface is responsible for the unusual behavior. Within this mechanism an excited electron in a conduction band is trapped at the defect. Then a Bound Exciton is formed between the trapped electron and a hole in a valence band. Based on this model the binding energy of a Bound Exciton is evaluated by the variational method, and the PL intensity from the Bound Exciton state is calculated. It is shown that the calculated binding energy of the Bound Exciton increases while the PL intensity decreases with increasing magnetic fields when the magnetic field is applied perpendicular to the superlattice layer. These results are consistent with the experimental data.
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Photoluminescence from Bound Exciton states in GaP/AlP short period superlattices in a strong magnetic field
Solid State Communications, 1999Co-Authors: Yuka Kobayashi, K. Kouzu, Hiroshi KamimuraAbstract:Abstract In (GaP) n (AlP) n superlattices the photoluminescence (PL) intensity decreases with increasing magnetic field in the strong field regime in the Faraday configuration. The origin of this unusual behavior of photoluminescence is discussed. In this article we show that a Bound Exciton trapped at a defect at the interface is responsible for the unusual behavior. Within this mechanism an excited electron in a conduction band is trapped at the defect. Then a Bound Exciton is formed between the trapped electron and a hole in a valence band. Based on this model the binding energy of a Bound Exciton is evaluated by the variational method, and the PL intensity from the Bound Exciton state is calculated. It is shown that the calculated binding energy of the Bound Exciton increases while the PL intensity decreases with increasing magnetic fields when the magnetic field is applied perpendicular to the superlattice layer. These results are consistent with the experimental data.
Yuka Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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photoluminescence from Bound Exciton states in gap alp short period superlattices in a strong magnetic field
Solid State Communications, 1999Co-Authors: Yuka Kobayashi, K. Kouzu, Hiroshi KamimuraAbstract:Abstract In (GaP) n (AlP) n superlattices the photoluminescence (PL) intensity decreases with increasing magnetic field in the strong field regime in the Faraday configuration. The origin of this unusual behavior of photoluminescence is discussed. In this article we show that a Bound Exciton trapped at a defect at the interface is responsible for the unusual behavior. Within this mechanism an excited electron in a conduction band is trapped at the defect. Then a Bound Exciton is formed between the trapped electron and a hole in a valence band. Based on this model the binding energy of a Bound Exciton is evaluated by the variational method, and the PL intensity from the Bound Exciton state is calculated. It is shown that the calculated binding energy of the Bound Exciton increases while the PL intensity decreases with increasing magnetic fields when the magnetic field is applied perpendicular to the superlattice layer. These results are consistent with the experimental data.
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Photoluminescence from Bound Exciton states in GaP/AlP short period superlattices in a strong magnetic field
Solid State Communications, 1999Co-Authors: Yuka Kobayashi, K. Kouzu, Hiroshi KamimuraAbstract:Abstract In (GaP) n (AlP) n superlattices the photoluminescence (PL) intensity decreases with increasing magnetic field in the strong field regime in the Faraday configuration. The origin of this unusual behavior of photoluminescence is discussed. In this article we show that a Bound Exciton trapped at a defect at the interface is responsible for the unusual behavior. Within this mechanism an excited electron in a conduction band is trapped at the defect. Then a Bound Exciton is formed between the trapped electron and a hole in a valence band. Based on this model the binding energy of a Bound Exciton is evaluated by the variational method, and the PL intensity from the Bound Exciton state is calculated. It is shown that the calculated binding energy of the Bound Exciton increases while the PL intensity decreases with increasing magnetic fields when the magnetic field is applied perpendicular to the superlattice layer. These results are consistent with the experimental data.
Subhananda Chakrabarti - One of the best experts on this subject based on the ideXlab platform.
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detection of acceptor Bound Exciton peak at 300 k in boron phosphorus co doped znmgo thin films for room temperature optoelectronics applications
Optical Materials, 2020Co-Authors: Sushama Sushama, Punam Murkute, Hemant Ghadi, Sushil Kumar Pandey, Subhananda ChakrabartiAbstract:Abstract It is well-known that the ZnMgO thin-film faces a roadblock in its potential applications for various optoelectronic devices due to the limitation imposed on achieving p-type conduction. The mono-acceptor doping of ZnMgO endures from the stern self-compensation by native donor defects and deep acceptor level formation advocating the need for alternate doping techniques like co-doping. In this paper, we report a detailed study on the improvement in structural, elemental, and optical properties of phosphorus-doped Zn0.85Mg0.15O thin films, with an aim to obtain enhancement in the signatures of acceptor-doped behavior, under the influence of boron implantation time. In addition, the paper also captures the behavior exhibited by the co-doped samples as a result of the variation in the annealing temperature. The solubility of the phosphorus atom (acceptor dopant) was observed to improve with boron (donor co-dopant) implantation as confirmed by the structural, elemental, and optical properties of co-doped ZnMgO thin films. It was also found that the acceptor level emissions got improved after boron implantation in phosphorus-doped ZnMgO thin films. Additionally, with co-doping, the sample showed the signature of acceptor-Bound Exciton peak till 300 K, evidencing the room-temperature operability of the films. Moreover, the fabricated film had a shallow acceptor energy level located at around 74 ± 0.45 meV above the valence band. Co-doped samples also showed stable acceptor based optical emission for more than a year.
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the impact of time varying phosphorus doping on znmgo thin films and achievement of dominant acceptor Bound Exciton peak
Proceedings of SPIE, 2015Co-Authors: Shantanu Saha, S Nagar, S Gupta, Subhananda ChakrabartiAbstract:ZnO is a highly efficient and promising semiconductor material because of its large bandgap (3.37 eV) and Exciton binding energy (60 meV). MgO also has a very high bandgap (7.8 eV), and the incorporation of Mg into ZnO can result in an alloy with a bandgap of more than 4 eV . We used plasma immersion ion implantation to dope phosphorus into Zn0.85Mg0.15O for achieving p-type ZnMgO. RF sputtering was used to deposit ZnMgO on a Si substrate. Phosphorus doping was conducted from 10 s to 70 s. Rapid thermal annealing of the samples was performed to remove any implantation defects. A highly dominant acceptor-Bound-Exciton peak was observed at 3.36 eV by photoluminescence measurements, which continued to dominate from low temperature to room temperature. Donor-Bound acceptor and free-electron acceptor peaks were also observed at 3.24 eV and 3.28 eV, respectively.
J Y Lin - One of the best experts on this subject based on the ideXlab platform.
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acceptor Bound Exciton transition in mg doped aln epilayer
Applied Physics Letters, 2004Co-Authors: Neeraj Nepal, J Y Lin, M L Nakarmi, K B Nam, H X JiangAbstract:Mg-doped AlN epilayers grown by metalorganic chemical-vapor deposition have been studied by deep ultraviolet time-resolved photoluminescence (PL) spectroscopy. A PL emission line at 6.02eV has been observed at 10K in Mg-doped AlN, which is about 40meV below the free-Exciton transition in undoped AlN epilayer. Temperature dependence of the PL intensity of this emission line also reveals a binding energy of 40meV. This transition line is believed to be due to the recombination of an Exciton Bound to neutral Mg acceptor (I1) with a binding energy of Ebx=40meV. This value is also about 10% of the energy level of Mg impurity in AlN satisfying Haynes’ rule. The recombination lifetime of the I1 transition in Mg-doped AlN has been measured to be 130ps, which is close to the expected value. The larger Ebx of the acceptor-Bound Exciton in AlN than that in GaN is due to large effective masses of the electrons and holes, as well as the energy level of Mg impurity.
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time resolved photoluminescence studies of an ionized donor Bound Exciton in gan
Applied Physics Letters, 1999Co-Authors: R A Mair, J Y Lin, S K Duan, H X JiangAbstract:Time-resolved photoluminescence (PL) spectroscopy has been used to study the radiative recombination of Excitons Bound to ionized donors in GaN doped with both Mg and Si at concentrations of 5×1018/cm3 and 1.5×1017/cm3, respectively. Low temperature (T∼10K) time-resolved, as well as integrated PL spectra, identify an ionized donor-Bound (Si) Exciton peak (D+X) approximately 11.5 meV below and a neutral acceptor-Bound Exciton (A0X) 20.5 meV below the free Exciton peak. Rapid decay of the free Exciton emission (⩽20 ps) implies that Excitons are quickly captured by acceptors and ionized donors. We find the (A0X) emission lifetime is consistent with previous measurements for GaN:Mg epilayers, while the (D+X) lifetime of 160 ps is longer than that of the well studied neutral donor-Bound Exciton (D0X). The measured (D+X) lifetime, in comparison with (D0X) and (A0X), suggests that the state is stable at low temperature.
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acceptor Bound Exciton recombination dynamics in p type gan
Applied Physics Letters, 1995Co-Authors: M Smith, Guangde Chen, J Y Lin, H X Jiang, Asif M Khan, C J SunAbstract:Dynamics of the neutral‐acceptor‐Bound Exciton transition (the I1 line) in a Mg doped p‐type GaN epitaxial layer grown by metalorganic chemical vapor deposition (MOCVD) have been studied by time‐resolved photoluminescence emission spectroscopy. Two emission lines in the I1 transition region have been resolved in the time‐resolved spectra, possibly due to the existence of two energy states of the Mg impurities after postgrowth thermal annealing. The recombination lifetimes of the acceptor‐Bound Exciton transition have been measured under different conditions including temperature, excitation intensity, and emission energy. From these measurements, a value of about 450 ps for the radiative recombination lifetime has been obtained, which is an important physical quantity for optoelectronic device applications based on GaN.
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neutral donor Bound Exciton recombination dynamics in gan grown by metalorganic chemical vapor deposition
Applied Physics Letters, 1995Co-Authors: M Smith, Guangde Chen, J Y Lin, H X Jiang, Asif M Khan, C J SunAbstract:Neutral‐donor‐Bound Exciton recombination (I2) dynamics have been studied by photoluminescence in an unintentionally doped n‐type GaN epitaxial layer grown by metalorganic chemical vapor deposition. The luminescence emission line shape, peak position, and intensity as functions of temperature have been measured. In particular, time‐resolved emission spectroscopy has been employed to study the dynamic processes of the Bound Exciton recombination, from which the temperature and the emission energy dependencies of the recombination lifetime of this transition have been obtained.