High-performance broadband photodetector with in-situ-grown Bi2Se3 film on micropyramidal Si substrate

Fabrication and Characterization of a Self-Powered n-Bi2Se3/p-Si Nanowire Bulk Heterojunction Broadband Photodetector

“…The rapid rise and fall times can be ascribed to the bulk heterojunction that can facilitate the dissociating of photo-generated carriers and their transportation to the metal electrode. In comparison to the performance of the Bi 2 Se 3 /n-Si photodetector, our photodetector had a longer detection wavelength than that reported by C. Liu et al [ 18 ] and H. Zhang et al [ 16 ], but was shorter than that reported by X. Hong et al [ 17 ]. However, the responsivity of our photodetector was 10 5 times better than theirs at the wavelength of ~1.5 µm, which was due to our Bi 2 Se 3 film that was thicker than theirs.…”

“…However, it has an indirect bandgap of 1.12 eV at room temperature, which means that it cannot detect infrared light with a wavelength >1.1 μm, including the two important communication wavelengths 1.3 μm and 1.55 μm. In order to extend the silicon detection wavelength, Bi 2 Se 3 has been used to deposit onto silicon to form a heterojunction infrared detector [ 16 , 17 , 18 , 19 ]. Hongbin Zhang et al [ 16 ] fabricated Bi 2 Se 3 by the physical vapor deposition (PVD) method inside a horizontal tube furnace, and the Bi 2 Se 3 /n-Si photodetector with a detection range of 350 nm to 1100 nm, a responsivity of 24.28 A/W, a detectivity of 4.39 × 10 12 Jones, a rise time (t r ) of 2.5 μs and a fall time (t f ) of 5.5 μs.…”

“…Hongbin Zhang et al [ 16 ] fabricated Bi 2 Se 3 by the physical vapor deposition (PVD) method inside a horizontal tube furnace, and the Bi 2 Se 3 /n-Si photodetector with a detection range of 350 nm to 1100 nm, a responsivity of 24.28 A/W, a detectivity of 4.39 × 10 12 Jones, a rise time (t r ) of 2.5 μs and a fall time (t f ) of 5.5 μs. Additionally, Xin Hong et al [ 17 ] fabricated Bi 2 Se 3 film on a micropyramidal Si substrate also by the PVD method inside a tube furnace, and the photodetector had a response wavelength range of 635 to 2700 nm, a photo-to-dark ratio of 1.01 × 10 4 , a dark current of 0.11 nA, a t r of 0.52 ms and a t f of 0.44 ms. Liu C et al [ 18 ] fabricated Bi 2 Se 3 nanowires on the n-Si substrate by an Au-catalyzed vapor–liquid–solid (VLS) method, and its photodetector had a response wavelength range of 380 to 1310 nm, a photo-to-dark ratio of 10, a responsivity of 924.2 A/W, a t r of 45 ms and a t f of 47 ms. Since Bi 2 Se 3 is an intrinsic n-type material, we believe that n-Bi 2 Se 3 /p-silicon heterojunction is more favorable for electron transportation [ 19 ].…”

“…Figure S15: Energy-band diagrams for an n-Bi 2 Se 3 /p-Si NWs heterostructure photodetector. Table S1: Performance comparison of our Bi 2 Se 3 /Si NWs photodetector with previous Bi 2 Se 3 /Si photodetectors [ 16 , 17 , 18 , 19 , 21 , 51 , 52 ].…”

Self-Powered Bi2Se3/Si Position-Sensitive Detector and Its Performance Enhancement by Introducing a Si Nanopyramid Structure

“…Fortunately, the recent results demonstrate that the combination of Bi 2 Se 3 with traditional Si semiconductor arouses great concern because of its mature process, low price, and abundant properties, all of which play an important role in large-scale integrated devices. − Moreover, the helical characteristics of the Bi 2 Se 3 topological surface can effectively suppress electron backscattering and enhance carrier mobility, and an obvious exciton gain behavior can be obtained when combining with the Si material . Besides, Bi 2 Se 3 belongs to a triangular crystal system with a layered structure, in which the single molecular layer consists of five atomic layers of Se(1)–Bi–Se(2)–Bi–Se(1) bonded covalently with van der Waals forces between two layers with a layer spacing of about 1 nm, so that high-quality thin films can be easily deposited on the Si substrates by pulsed laser deposition (PLD), metal-organic chemical vapor deposition (MOCVD), and molecular beam epitaxy (MBE). − Based on these advantages, some researchers have begun to prepare Bi 2 Se 3 /Si heterostructure, intending to fully utilize their respective excellent properties to achieve a synergistic effect.…”