Photoinduced entropy of InGaN/GaN p-i-n double-heterostructure nanowires

Alfaraj, Nasir; Mitra, Somak; Wu, Feng; Ajia, Idris A.; Janjua, Bilal; Prabaswara, Aditya; Aljefri, Renad A.; Sun, Haiding; Ng, Tien Khee; Ooi, Boon S.; Roqan, Iman S.

doi:10.1063/1.4981252

Cited by 52 publications

(42 citation statements)

References 53 publications

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“…69 Because quantum confinement effects are absent in our nanowires, less efficient radiative recombination of photoexcited carriers is achieved, although the possible presence of grain-boundary-induced carrier localization effects enhances the radiative recombination efficiency. As we previously noted, 40 the entropy of a system sets an upper limit on the number of emitted photons from an active region and is always positive-emitted photons transport entropy produced by the absorption of heat from the active region. [70][71][72] We recall our definition of the change in entropy S due to photoexcitation and photoemission 40 …”

Section: A Sample Description and Experimental Setupmentioning

confidence: 91%

“…As we previously noted, 40 the entropy of a system sets an upper limit on the number of emitted photons from an active region and is always positive-emitted photons transport entropy produced by the absorption of heat from the active region. [70][71][72] We recall our definition of the change in entropy S due to photoexcitation and photoemission 40 …”

Section: A Sample Description and Experimental Setupmentioning

confidence: 91%

“…We recalled our definition of photoinduced entropy as a thermodynamic measure of the unavailability of a system's energy for conversion into useful work because of luminescence refrigeration. [40][41][42] We also examined the dynamics of photocarriers using time-resolved photoluminescence (TRPL) down to the picosecond regime. Fig.…”

Section: A Sample Description and Experimental Setupmentioning

confidence: 99%

“…The nanowires were grown using plasma-assisted MBE. 35,40 The nanowires consisted of 10 nm unintentionally-doped GaN nanobuffers and approximately 290 nm unintentionally doped AlGaN layers grown sequentially. Before the growth of AlGaN, thin GaN nanowire array template was grown to promote the formation of AlGaN nanowires.…”

Section: A Sample Description and Experimental Setupmentioning

confidence: 99%

“…38,39 As a consequence of the thermal activation of non-radiative recombination channels, we observed an increasing trend in the amount of generated photoinduced entropy of the InGaN nanowire system as its temperature approached room temperature, which is a valid assessment of the thermodynamic disorder in photoluminescent semiconducting materials. 40 Furthermore, the non-radiative photocarrier recombination lifetimes in nanostructured materials are naturally shorter than those of bulk structures owing to their higher surface-to-volume ratios.…”

Section: Introductionmentioning

confidence: 99%

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Thermodynamic photoinduced disorder in AlGaN nanowires

Alfaraj

Muhammed

et al. 2017

AIP Advances

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In this study, we examine thermodynamic photoinduced disorder in AlGaN nanowires through their steady-state and transient photoluminescence properties. We correlate the energy exchange during the photoexcitation and photoemission processes of the light–solid reaction and the generation of photoinduced entropy of the nanowires using temperature-dependent (6 K to 290 K) photoluminescence. We observed an oscillatory trend in the generated entropy of the system below 200 K, with an oscillation frequency that was significantly lower than what we have previously observed in InGaN/GaN nanowires. In contrast to the sharp increase in generated entropy at temperatures close to room temperature in InGaN/GaN nanowires, an insignificant increase was observed in AlGaN nanowires, indicating lower degrees of disorder-induced uncertainty in the wider bandgap semiconductor. We conjecture that the enhanced atomic ordering in AlGaN caused lower degrees of disorder-induced uncertainty related to the energy of states involved in thermionic transitions; in keeping with this conjecture, we observed lower oscillation frequency below 200 K and a stable behavior in the generated entropy at temperatures close to room temperature.

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Section: A Sample Description and Experimental Setupmentioning

confidence: 91%

Section: A Sample Description and Experimental Setupmentioning

confidence: 91%

Section: A Sample Description and Experimental Setupmentioning

confidence: 99%

Section: A Sample Description and Experimental Setupmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Thermodynamic photoinduced disorder in AlGaN nanowires

Alfaraj

Muhammed

et al. 2017

AIP Advances

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Heteroepitaxial β‐Ga₂O₃ on Conductive Ceramic Templates: Toward Ultrahigh Gain Deep‐Ultraviolet Photodetection

Alfaraj

Alawein

et al. 2021

Adv Materials Technologies

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This article investigates the ultrahigh sensitivity and DUV photodetection capability of a hybrid oxide‐nitride stack comprising β‐Ga2O3 layers grown heterogeneously on a conductive ceramic crystal. The ceramic crystal, namely a TiN interlayer, which acts as a lattice template, was heteroepitaxially grown on bulk MgO. Because β‐Ga2O3 is a monoclinic phase crystal, it is conjectured that its nucleation and growth process on cubic phase TiN is entropic in nature, whereby the two unit cell configurations of the β‐Ga2O3 crystal, exhibiting rotational twin domains, grew alternately side by side in a semiperiodic manner on TiN while maintaining a single crystal phase. This film formation mechanism contributed to the introduction of additional defects in the β‐Ga2O3 lattice (Taylor's dislocations in addition to growth‐induced vacancies). The fabricated DUV photodetectors based on the resulting metal‐semiconductor junction heterodiodes exhibited an average peak spectral responsivity of 276.72 A W−1 and fast decay constants in the order of 500 ms in the ultraviolet‐C regime, with true solar‐blind characteristics manifested by ultraviolet‐to‐visible rejection ratios of up to 2 × 103 and illuminating power density of around 70 μW cm−2. The crystallographic orientation relationships between the TiN and β‐Ga2O3 crystals, as well as the lattice fit and dislocation types, are revealed and examined.

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Novel P‐Type Wide Bandgap Manganese Oxide Quantum Dots Operating at Deep UV Range for Optoelectronic Devices

Mitra

Pak

Alaal

et al. 2019

Advanced Optical Materials

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in a wide range of industrial applications, such as homeland security, medical diagnostics, food curing, sanitation, chemical and biological threat detection, space-tospace communications, missile detection, military surveillance, target detection and acquisition, transparent thin-film transistors, solar cells, white lighting, sterilization, medical treatment, and touch display panels. [1][2][3][4][5][6][7] For example, the most commercial DUV photodetectors are produced using UV-enhanced narrow bandgap semiconductors, mainly Si-based photodetector. [8,9] However, the narrow bandgap materials are ineffective in rejecting signals in the UV−vis−IR spectral region, making them unsuitable for DUV applications. Thus, high-quality DUV WBGSs are still needed to produce high-performance DUV optoelectronic devices. In each of the aforementioned fields, scientists and industry practitioners are looking to overcome different challenges. There is a growing demand for both p-type and n-type WBGSs that possess good stability and conductivity. The main obstacle to the achievement of this goal stems from the lack of p-type wide bandgap materials operating in the DUV range below 300 nm (i.e., >4.1 eV) that exhibit good p-type stability. Currently, the p-type materials having bandgap in the UV-A range (such as p-type GaN, Cu 2 O, and SnO) are utilized in DUV optoelectronics, which severely downgrade device performance, as their bandgaps are limited to the UV-A-to-visible spectral region (320-400 nm). [10,11] Moreover, though n-type WBGSs (e.g., ZnO, Ga 2 O 3 , and AlGaN) with good conductivity and stability can operate in the UV and DUV range (280−390 nm), it is not possible to convert them to a p-type material with good stability and conductivity due to their intrinsic electronic properties. [2,6,[11][12][13][14][15][16] Consequently, no highly stable conductive p-type DUV WBGS operating in both UV-B and UV-C region presently exists. [17] Further advances in the field of DUV optoelectronics are hindered by other issues, such as the difficulty in developing new cost-effective material production and fabrication methods that could replace the expensive and high vacuum-based technologies presently in use. Thus, as DUV-WBGS based devices tend Wide bandgap semiconductor (WBGS)-based deep UV (DUV) devices lag behind those operating in the visible and IR range, as no stable p-type WBGS that operates in the DUV region (<300 nm) presently exists. Here, solutionprocessed p-type manganese oxide WBGS quantum dots (MnO QDs) are explored. Highly crystalline MnO QDs are synthesized via femtosecond-laser ablation in liquid. The p-type nature of these QDs is demonstrated by Kelvin probe and field effect transistor measurements, along with density functional theory calculations. As proof of concept, a high-performance, self-powered, and solar-blind Schottky DUV photodetector based on such QDs is fabricated, which is capable of detecting under ambient conditions. The carrier collection efficiency is enhanced by asymmetric electrode structure, leadi...

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Photoinduced entropy of InGaN/GaN p-i-n double-heterostructure nanowires

Cited by 52 publications

References 53 publications

Thermodynamic photoinduced disorder in AlGaN nanowires

Thermodynamic photoinduced disorder in AlGaN nanowires

Heteroepitaxial β‐Ga₂O₃ on Conductive Ceramic Templates: Toward Ultrahigh Gain Deep‐Ultraviolet Photodetection

Novel P‐Type Wide Bandgap Manganese Oxide Quantum Dots Operating at Deep UV Range for Optoelectronic Devices

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Photoinduced entropy of InGaN/GaN p-i-n double-heterostructure nanowires

Cited by 52 publications

References 53 publications

Thermodynamic photoinduced disorder in AlGaN nanowires

Thermodynamic photoinduced disorder in AlGaN nanowires

Heteroepitaxial β‐Ga2O3 on Conductive Ceramic Templates: Toward Ultrahigh Gain Deep‐Ultraviolet Photodetection

Novel P‐Type Wide Bandgap Manganese Oxide Quantum Dots Operating at Deep UV Range for Optoelectronic Devices

Contact Info

Product

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Heteroepitaxial β‐Ga₂O₃ on Conductive Ceramic Templates: Toward Ultrahigh Gain Deep‐Ultraviolet Photodetection