RESUMEN
Gallium oxide (Ga2O3) possesses a band gap of approximately 4.9 eV, aligning its detection wavelength within the solar-blind region, making it an ideal semiconductor material for solar-blind photodetectors. This study aims to enhance the performance of Ga2O3ultraviolet (UV) detectors by pre-depositing a Ga2O3seed layer on ac-plane sapphire substrate. The x-ray diffraction and x-ray photoelectron spectroscopy analyses validated that the deposited films, following high-temperature annealing, comprisedß-Ga2O3. Comparing samples with and without a 20 nm seed layer, it was found that the former exhibited fewer oxygen defects and substantially improved crystal quality. The incorporation of the seed layer led to the realization of detectors with remarkably low dark current (≤15.3 fA). Moreover, the photo-to-dark current ratio was enhanced by 30% (surpassing 1.3 × 104) and the response/recovery time reduced to 0.9 s/0.01 s, indicating faster performance. Furthermore, these detectors demonstrated higher responsivity (4.8 mA W-1), improved detectivity (2.49 × 1016Jones), and excellent solar-blind characteristics. This study serves as a foundational stepping toward achieving high-qualityß-Ga2O3thin film and UV detector arrays.
RESUMEN
In this work, SnO2 hollow microspheres functionalized with different incorporated amounts of Pt@Co3O4 complex catalyst were innovatively designed by using an MOF template. The results show that sensor based on the optimal incorporated amount of Pt@Co3O4 not only greatly enhances the response value of SnO2 to formaldehyde (Rair/Rformaldehyde = 4240 toward 100 ppm) but also decreases the low detection limit (50 ppb), which is quite outstanding compared with other SnO2-based formaldehyde sensors. Further analysis proves that the content of oxygen vacancy and chemisorbed oxygen and the catalytic effect of ultra-small Pt play the key roles in improving the formaldehyde sensing performance. Meanwhile, this present work demonstrates that oxide semiconductors functionalized with the derivatives of MOF templated catalysts may lead to the discovery of new material systems with outstanding sensing performance.
