Size- and Phase-Controlled Nanometer-Thick β-Ga₂O₃ Films with Green Photoluminescence for Optoelectronic Applications

Abstract

Realization and optimization of the tunable/enhanced optical properties are critical to further advancing the fields of optoelectronics, photonics, and nanoelectronics. In this context, here, we demonstrate green-emission characteristics with a ∼30-fold enhancement in selectively engineered nanocrystalline Ga 2 O 3 with control over the size, phase, and interface nanostructure. Pulsed-laserdeposited β-phase Ga 2 O 3 films with an average crystallite size of ∼9 nm along with a highly dense, close-compact nanocolumnar structure with the lowest possible defect density facilitate the 30-fold enhancement in the photoluminescence (PL) intensity in the green region. Enhanced PL emission in the optimized, engineered nanoarchitecture sheds light on the design of Ga 2 O 3 materials for promising future optoelectronic/ photocatalytic applications.

Interfacial Phase Modulation-Induced Structural Distortion, Band Gap Reduction, and Nonlinear Optical Activity in Tin-Incorporated Ga2O3

“…The chemistry behind the band gap variation (Figure ) in the Ga-Sn-O compounds can be understood as follows. The band gap of pure Ga 2 O 3 is ∼4.75 eV, which is in good agreement with the literature values reported for Ga 2 O 3 bulk or polycrystalline materials. − In intrinsic β-Ga 2 O 3 , the valence band edge is dominantly formed by the O-2p orbitals, while that of the conduction band is primarily formed by the Ga-4s orbitals. However, the effect of hybridization becomes the important process governing the electronic structure changes upon Sn incorporation.…”

“…Recently, gallium oxide (Ga 2 O 3 ) has been receiving significant attention from the scientific and engineering research communities because of its diverse structural chemistry, physical and chemical properties, novel phenomena, and technological applications. − The ability for integration into numerous scientific and technological applications, which include utilization in electronics, optoelectronics, neuromorphic engineering, energy storage and conversion, catalysis, and chemical sensors, has given Ga 2 O 3 and Ga 2 O 3 -based alloys immense recognition in the mainstream of current research topics. − The specific application potential of these materials includes, but not limited to, the design and development of deep ultraviolet (UV) photodetectors, field-effect transistors (FETs), high-power electronic devices, sensors, solar cells, transparent conducting oxides (TCOs), cost-effective light-emitting diodes (LEDs), liquid eutectic contact, and photocatalysts. − …”

“…The enormous interest in Ga 2 O 3 is primarily derived from its thermodynamic stability and wide band gap. − ,, The band gap of β-Ga 2 O 3 is ∼4.8 eV, although the reported values vary in the range of 4.5–5.0 eV based on the methods employed for synthesis. − The wide band gap of β-Ga 2 O 3 corresponds to the second largest after that of diamond and is considerably greater than those of other TCOs such as In 2 O 3 , SnO 2 , and ZnO. Even after decades of research around β-Ga 2 O 3 , it has been only in the last decade or so that research interest has picked up momentum to utilize their extreme properties.…”

“…8−18 The enormous interest in Ga 2 O 3 is primarily derived from its thermodynamic stability and wide band gap. [1][2][3][4][5][6][7]18,19 The band gap of β-Ga 2 O 3 is ∼4.8 eV, although the reported values vary in the range of 4.5−5.0 eV based on the methods employed for synthesis. 1−18 The wide band gap of β-Ga 2 O 3 corresponds to the second largest after that of diamond and is considerably greater than those of other TCOs such as In 2 O 3 , SnO 2 , and ZnO.…”

Модифікація електронних властивостей надтонких плівок β-Ga2O3 механічними впливами

“…Gallium oxide can be easily doped, which makes it possible to obtain conductive layers of this material. 𝛽-Ga 2 O 3 can be grown in large amounts and used in UV photodetectors, photocatalysts, gas sensors, solar panels, transparent conductive filters for electrodes of various optoelectronic devices, and so forth [8][9][10][11][12][13][14][15][16][17][18][19].…”