We report an investigation of a planar GeSn p–i–n diode for a high-detectivity photodetector based on an undoped GeSn film. By fabricating n- and p-type regions on the plane of the GeSn film using the complementary metal–oxide–semiconductor technology of ion implantation, a low dark current density is revealed and attributed to the low defect density of the film and current flow suppression around the diode periphery. This yields a specific 1550-nm detectivity of ∼1010 cm Hz1/2 W−1, an order of magnitude higher than that of conventional vertical GeSn-based diodes and comparable to that of commercially available Ge-based diodes. This work provides an alternative approach for achieving a high-detectivity GeSn photodetector that may facilitate its potential applications.

中文翻译：

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用于 1550 nm 高探测率光电探测的平面 GeSn 光电二极管

我们报告了对基于未掺杂 GeSn 薄膜的高探测率光电探测器的平面 GeSn p-i-n 二极管的研究。通过使用离子注入的互补金属-氧化物-半导体技术在 GeSn 薄膜平面上制造 n 型和 p 型区域，揭示了低暗电流密度，这归因于薄膜的低缺陷密度和电流流动抑制围绕二极管外围。这产生了~1010 cm Hz1/2 W-1 的特定 1550 nm 探测率，比传统的垂直 GeSn 基二极管高一个数量级，并且与市售的 Ge 基二极管相当。这项工作为实现高探测率 GeSn 光电探测器提供了一种替代方法，可以促进其潜在应用。