This study describes the optoelectronic characteristics of CuFeS₂/Si nanocrystal/bulk heterojunctions. These heterojunctions show a strong photocurrent response under ambient conditions upon excitation from a wide optical spectrum, from 460 to 2200 nm. The devices comprise of a heterojunction formed between heavily doped n‐type silicon (1–100 Ω cm) and copper iron sulfide (CuFeS₂) nanocrystal films. Over the spectral range 460–2200 nm the device shows a fast response (20 µs at NIR wavelengths), along with responsivity and detectivity of 4.68 mA W⁻¹ and 5.29 × 10⁹ Jones at 1900 nm wavelength. The photocurrent is further observed to be a nonlinear function of power. These properties of the devices are discussed in terms of a defect filling mechanism. Besides their regular photoresponse described above, the devices also exhibit a slower photothermal response, allowing these to also sense hot objects (450 K; excess 6 mW incident onto the device) within the focal plane, thereby extending the useful sensing range of the devices deeper into the infrared.

中文翻译：

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用于宽带光检测的硫化铜铁纳米晶体-体硅异质结

这项研究描述了CuFeS ₂ / Si纳米晶体/本体异质结的光电特性。这些异质结在环境条件下从460至2200 nm的宽光谱激发后显示出很强的光电流响应。该器件由在重掺杂n型硅（1–100Ωcm）和硫化铜铁（CuFeS ₂）纳米晶体薄膜之间形成的异质结组成。在460-2200 nm的光谱范围内，该器件显示出快速响应（在NIR波长下为20 µs），以及4.68 mA W ^-1和5.29×10 ^9的响应度和检测率。琼斯在1900 nm波长处。进一步观察到光电流是功率的非线性函数。根据缺陷填充机制来讨论设备的这些属性。除了上面描述的常规光响应外，这些器件还表现出较慢的光热响应，从而使它们还可以感测焦平面内的高温物体（450 K；入射到器件上的多余6 mW），从而将器件的有用感测范围更深地扩展了进入红外线。