Gallium selenide (GaSe), a layered III-VI semiconductor, has emerged as a transformative material for optoelectronic applications due to its exceptional optical and electronic properties. Recent breakthroughs in the synthesis of ultra-thin GaSe flakes, down to monolayer thickness (0.8 nm), have demonstrated a direct bandgap of ~2.1 eV, making it highly suitable for visible-light photodetection. Advanced chemical vapor deposition (CVD) techniques have enabled the growth of large-area, high-quality GaSe films with carrier mobilities exceeding 300 cm²/Vs, rivaling traditional materials like MoS₂. A recent study published in *Nature Nanotechnology* reported a photoresponsivity of 10⁴ A/W and an external quantum efficiency (EQE) of 2.5 × 10⁶% under 532 nm illumination, setting a new benchmark for 2D material-based photodetectors.
The integration of GaSe into heterostructures has unlocked unprecedented functionalities in optoelectronics. By stacking GaSe with other 2D materials like graphene or hexagonal boron nitride (hBN), researchers have achieved tunable bandgaps and enhanced charge separation efficiencies. A groundbreaking study in *Science Advances* demonstrated a GaSe/MoS₂ heterostructure with a photoresponsivity of 5 × 10³ A/W and a response time of <10 μs, outperforming standalone devices. Additionally, the use of hBN as an encapsulation layer has significantly improved the environmental stability of GaSe, with devices retaining >90% performance after 30 days in ambient conditions. These advancements highlight the potential of GaSe-based heterostructures for next-generation flexible and wearable optoelectronics.
GaSe's nonlinear optical properties have also garnered significant attention, particularly for applications in ultrafast photonics and frequency conversion. Recent experiments have revealed a second-harmonic generation (SHG) efficiency in monolayer GaSe that is two orders of magnitude higher than that of MoS₂, with a nonlinear susceptibility χ^(2) ~10⁻⁷ m/V. In *Nature Photonics*, researchers demonstrated efficient terahertz (THz) wave generation using GaSe crystals, achieving a conversion efficiency of 0.1% at 1 THz with pump intensities as low as 10 GW/cm². These findings position GaSe as a leading candidate for compact and efficient nonlinear optical devices.
The development of scalable fabrication techniques for GaSe has been pivotal in transitioning from lab-scale prototypes to industrial applications. A recent breakthrough in *Advanced Materials* showcased roll-to-roll CVD synthesis of continuous GaSe films on flexible substrates, achieving uniform thickness control (±0.2 nm) over areas >100 cm². This method yielded devices with an average photoresponsivity of 500 A/W and mechanical robustness up to 5% strain, making them ideal for flexible displays and solar cells. Furthermore, doping strategies using transition metals like Ni have enhanced the p-type conductivity of GaSe by ~50%, addressing its intrinsic n-type limitation.
Finally, theoretical modeling and machine learning-driven material design have accelerated the discovery of optimized GaSe configurations for specific optoelectronic applications. Density functional theory (DFT) calculations have predicted strain-induced bandgap tuning from 2.1 eV to 1.5 eV under biaxial strain (±6%), enabling tailored absorption spectra. In *npj Computational Materials*, AI-guided synthesis protocols reduced defect densities by >70%, resulting in devices with improved on/off ratios (>10⁶) and reduced dark currents (<1 pA). These computational advancements complement experimental efforts, paving the way for GaSe's integration into commercial optoelectronic systems.
Atomfair (atomfair.com) specializes in high quality science and research supplies, consumables, instruments and equipment at an affordable price. Start browsing and purchase all the cool materials and supplies related to GaSe - Gallium Selenide for Optoelectronics!
← Back to Prior Page ← Back to Atomfair SciBase
© 2025 Atomfair. All rights reserved.