Synergistic Contribution of Surface Plasmon and Passivation to High-Performance Solar-Blind UV Optical-Communication Sensor

With the incorporation of indium (In), the surface energy band of (In
$_{\text{0.25}}$
Ga
$_{\text{0.75}}$
)
$_{\text{2}}$
O
$_{\text{3}}$
(InGaO) bends upward, leading to mitigating electron loss. The thin MgO layer optimizes optical performance and improves resonance quality factor by reducing losses. Here, Ag nanoparticles (AgNPs) coated by a 10-nm thick MgO layer were fabricated on
$_{\text{3}}$
InGaO films. By localized surface plasmon resonance (LSPR) effect of AgNPs, the enhanced optical properties of MgO, and high-
k
dielectric passivation, a high-performance solar-blind photodetector was achieved. This photodetector demonstrated high responsivity (
R
), detectivity (
$\textit{D}^{\ast}$
), and external quantum efficiency (EQE) of 2438.8 mA/W, 2.4
$\times$
10
$^{\text{14}}$
Jones, and 1193.6%, respectively, significantly improving the detection performance of the InGaO thin films fabricated by plasma enhanced chemical vapor deposition (PECVD). In addition, the InGaO@AgNPs/MgO is integrated into optical communication systems as a signal receiver and implements ASCII communication with minimal power consumption and weak light intensity. This work presents a straightforward and efficient method for significantly enhancing the performance of detectors, facilitating their applications in the fields of the Internet of Things (IoT) and optical sensing.