Synergistic Additive‐Assisted Growth of 2D Ternary In₂SnS₄ with Giant Gate‐Tunable Polarization‐Sensitive Photoresponse

Abstract

2D ternary materials exhibit great promise in the field of polarization‐sensitive photodetectors due to the low‐symmetry crystal structure. However, the realization of ternary material growth is still a huge challenge because of the complex reaction process. Here, for the first time, 2D ternary In2SnS4 flakes are obtained via synergistic additive of salt and molecular sieve‐assisted chemical vapor deposition. Raman vibration mode of In2SnS4 flakes exhibits polarization‐dependent properties. The polarization‐resolved absorption spectroscopy and azimuth‐dependent reflectance difference microscopy further confirm its anisotropy of in‐plane optical absorption and reflection. Besides, the In2SnS4 flake based device on mica shows ultrafast rising and decay rates of ≈20 and 20 µs. Impressively, In2SnS4 flake based phototransistor demonstrates giant gate‐tunable polarization‐sensitive photoresponse: the dichroic ratio can be adjusted in the range of 1.13–1.70 with gate voltage varying from −35–35 V. This work provides an effective means for modulating the polarization‐sensitive photoresponse, which may significantly promote the research progress of polarization‐sensitive photodetectors.

Strong Anisotropic Two-Dimensional In2Se3 for Light Intensity and Polarization Dual-Mode High-Performance Detection

“…The correlation between crystal orientation and polarization is shown in Figure S8, considering that 2D materials usually dissociate along the zigzag, , we can see that the maximum photocurrent is along the armchair direction, while the minimum photocurrent is along the zigzag direction. Moreover, it is worth noting that the dichroic ratio of 2H α-In 2 Se 3 can reach 1.47 at 650 nm, which is well consisted with other anisotropic 2D materials such as MoTe 2 , 1T-PtTe 2 , and In 2 SnS 4 at 650 nm. Additionally, polarized-angle resolved photocurrent still exhibits typical polarization detection after 10 months of exposure, as shown in Figure c, indicating that 2H α-In 2 Se 3 exhibits good air stability, which is critical to the application.…”

“…As seen in Figure d, the dichroic ratio can be increased from 1.15 to 1.29, a 12% increase, as gate voltage increases from 0 to 20 V. However when the gate voltage increases to 40 V, the dichroic ratio decreases to 1.24. This might correlate with the anisotropic transport property of the 2H α-In 2 Se 3 where higher gate voltage would induce larger carrier concentration and suppress the contribution of the anisotropic transport …”

High-TC Two-Dimensional Ferroelectric CuCrS2 Grown via Chemical Vapor Deposition

“…The atomically flat, clean, and chemically inert surface, as well as the weak van der Waals interaction between the mica surface and precursors, allow the precursors to migrate with a relatively lower barrier, which is critical for 2D growth. , The mixed NaCl, copper, and chromium powders were used as metal precursors. Additional sodium chloride can lower the melting point of the precursors, guaranteeing a proper feeding rate. − Then, the precursors can diffuse steadily on the surface of mica substrate to realize the growth of CuCrS 2 nanoflakes. Different results with/without NaCl in the precursors are shown in Figure S1 (Supporting Information).…”

Recent Progress on Two-Dimensional Materials

“…Other intriguing properties of excitons like valley effect 415 , optical Stark effect 416,417 , exciton-phonon coupling 418 , linewidth and lifetime coherence 419 , transport behavior 420 and interlayer exciton absorptions [421][422][423] , are extensively studied. The lattice anisotropy induced polarization dependent optical responses are observed in BP 412,414 and other anisotropic 2D materials 416,[424][425][426][427][428][429] . Furthermore, absorption spectroscopy is a powerful tool to reveal unique excitonic properties modulated by external fields, including dielectric environment 430 , electrical filed 421,431,432 , and optomechanical fields 433 .…”