Superior Performances of Self‐Driven Near‐Infrared Photodetectors Based on the SnTe:Si/Si Heterostructure Boosted by Bulk Photovoltaic Effect

Abstract

The upsurge of new materials that can be used for near‐infrared (NIR) photodetectors operated without cooling is crucial. As a novel material with a small bandgap of ≈0.28 eV, the topological crystalline insulator SnTe has attracted considerable attention. Herein, this work demonstrates self‐driven NIR photodetectors based on SnTe/Si and SnTe:Si/Si heterostructures. The SnTe/Si heterostructure has a high detectivity D* of 3.3 × 1012 Jones. By Si doping, the SnTe:Si/Si heterostructure reduces the dark current density and increases the photocurrent by ≈1 order of magnitude simultaneously, which improves the detectivity D* by ≈2 orders of magnitude up to 1.59 × 1014 Jones. Further theoretical analysis indicates that the improved device performance may be ascribed to the bulk photovoltaic effect (BPVE), in which doped Si atoms break the inversion symmetry and thus enable the generation of additional photocurrents beyond the heterostructure. In addition, the external quantum efficiency (EQE) measured at room temperature at 850 nm increases by a factor of 7.5 times, from 38.5% to 289%. A high responsivity of 1979 mA W−1 without bias and fast rising time of 8 µs are also observed. The significantly improved photodetection achieved by the Si doping is of great interest and may provide a novel strategy for superior photodetectors.

Sputtered SnTe Thin Films on Si and Ge as a Plasmonic Material

“…In line with previous work, we are unable to obtain epitaxial growth of SnTe on Si via sputtering over a range of conditions. 24,27 We speculate, largely informed by extensive work on III−V-on-Si integration, that SnTe growth on Si requires high-temperature substrate bakes (in excess of 1100 °C for UHV 29 or 800 °C under H 2 ambient 30 ) to achieve a good surface step structure after removal of the native oxide. While this is not possible via a conventional sputtering chamber, the SnTe films on Si are an excellent candidate to understand the relationship between SnTe film crystallinity, sputtering conditions, carrier concentration, and the plasmonic properties of the SnTe films.…”

“…There are preliminary indications that sputtering can be used to realize SnTe films on technologically relevant substrates that are good plasmonic materials if a few obstacles are overcome. Epitaxial films of sputtered SnTe have been reported on NaCl substrates, but sputtered growth of SnTe films on MgO- and CMOS-compatible substrates of Si and Ge ,, has so far yielded polycrystalline films. It is important to understand whether polycrystalline growth is inevitable or if single crystal growth is possible on these CMOS-compatible substrates, given that SnTe ( a = 6.32 Å) has a relatively large lattice mismatch of 16.4% on Si ( a = 5.43 Å) and 11.6% on Ge ( a = 5.66 Å), respectively.…”

Effective Strategy for High‐Performance Organic Photodetectors with Significantly Suppressed Dark Current and Improved Responsivity

“…[10][11][12][13][14] Commercial photodetectors (PDs) are commonly based on inorganic semiconductors, such as silicon (Si), indium gallium arsenide (In-GaAs), and mercury cadmium telluride (MCT). [15,16] However, the rigidity and high-temperature processing requirements of inorganic semiconductors limit their applications in lightweight and flexible substrates. Developing new high-performance flexible materials and related devices for detection has been an important topic in the field of photoelectronics.…”

The effect of an external magnetic field on the interaction of carbon monoxide with hematite

“…18–28 However, the influence of the field on heterogeneous catalytic processes has been considered in relatively few publications, in particular the influence of a magnetic field on the FT synthesis. 29–33…”

“…In the review in ref 32,. the recent progress of magnetic field enhanced CO 2 capture and conversion was comprehensively summarized.…”