基于泄漏模式的 SiNW array/MAPbI_{3} 核壳结构异质结宽波段光电探测器

文章提出一种基于泄漏模式的核壳结构硅基p-n异质结宽波段光电探测器,该探测器在可见光到近红外光的宽波段范围内均具有良好的光响应,且在430 nm和970 nm波长处分别测得光电流峰值。研究发现,核壳结构的异质结与阶跃型折射率光纤的结构相似,高折射率的硅纳米线和涂覆的钙钛矿层分别充当了光纤中的纤芯和包层;当入射光的引导模式在核壳结构中转变为泄漏模式时,能量将从纤芯泄漏到包层中,从而增强了该波段的光学吸收。通过光学仿真软件COMSOL对器件的电场分布进行仿真,证实了异质结中存在泄漏模式。器件的性能分析结果表明,0 V偏压下,探测器在430 nm和970 nm波长处的最大响应度分别达到87 mA/W和694 mA/W。该研究表明,核壳结构中的泄漏模式可以增强入射光的吸收,基于泄漏模式制备的光电器件在未来具有较大的应用潜力。

This paper proposes a silicon based p-n heterojunction broadband photodetector with a core-shell structure induced by leaky mode. The detector is sensitive to a wide wavelength range from the visible light to near-infrared region. Remarkably, the photocurrent of the device exhibits two peaks at the wavelengths of 430 nm and 970 nm. It is found that the core-shell heterojunction has a similar structure to step-index fiber, with silicon nanowire(SiNW) serving as the core and perovskite thin films serving as the cladding. In the core-shell structure, when the guided mode of incident light changes to the leaky mode, energy will leak from the core to the cladding, resulting in enhanced optical absorption at that wavelength. The electric field distribution of the device was simulated using optical simulation software COMSOL, confirming the presence of leaky modes in the heterojunction. The device performance analysis shows that the peak responsivities of the detector under 430 nm and 970 nm wavelength can reach 87 mA/W and 694 mA/W, respectively, at zero bias voltage. This study demonstrates that the leaky mode present in core-shell structures can enhance the absorption of incident light, and optoelectronic devices based on leaky modes have great potential for future applications.