Tin selenide (SnSe) has attracted great attention in thermoelectrics (TE) thanks to its record high figure of merit (ZT) discovered in single crystal (SC). However, the practical application of SnSe SC is limited due to its extreme growth condition. With the development of flexible integrated electronics, using flexible polycrystalline TE films to substitute rigid SC becomes a main trend. Nevertheless, large resistances of TE films restricts their application as power devices. Here, self-powered SnSe-based photothermoelectric (PTE) detectors are demonstrated. The PTE detectors are sensitive to wide-spectrum and exhibit higher responsivity and respnse speed comparing with SC, due to the small heating volume, small conductive heat flux and large dissipation content of thin films. High-quality (400)-textured SnSe polycrystalline thin films are one-step synthesized by chemical vapor deposition. In-situ in-plane TE measurement shows that the obtained SnSe films possess a dimensionless ZT of 0.15 and a power factor of 0.322 mW m⁻¹ K^-2 at 550 K, showing SC level TE performance at low temperatures.

硒化锡（SnSe）因其创纪录的优异品质（ZT）而备受热电学（TE）的关注）在单晶（SC）中发现。然而，由于SnSe SC的极端生长条件，其实际应用受到限制。随着柔性集成电子器件的发展，使用柔性多晶TE薄膜代替刚性SC成为主要趋势。然而，TE膜的大电阻限制了它们作为功率器件的应用。这里，展示了基于SnSe的自供电光热电（PTE）检测器。PTE检测器对宽光谱敏感，并且与SC相比具有更高的响应度和响应速度，这是因为其发热量小，传导热通量小以及薄膜的耗散量大。高质量（400）纹理的SnSe多晶薄膜是通过化学气相沉积一步合成的。ZT为0.15，在550 K时的功率因数为0.322 mW m ^-1  K ^-2，在低温下显示SC级TE性能。