TlHgInS₃: An Indirect-Band-Gap Semiconductor with X-ray Photoconductivity Response

Abstract

The quaternary compound TlHgInS 3 crystallizes in a new structure type of space group C2/c with cell parameters: a = 13.916(3) Å, b = 3.9132(8) Å, c = 21.403(4) Å, β = 104.16(3)°, V = 1130.1(8) Å 3 and ρ = 7.241 g/cm 3 . The structure is a unique three-dimensional framework with parallel tunnels, which is formed by 1 ͚ [InS 33-] infinite chains bridged by linearly coordinated Hg 2+ ions. TlHgInS 3 is a semiconductor with a band gap of 1.74 eV and resistivity of ~4.32 GΩ cm.TlHgInS 3 single crystals exhibit photocurrent response when exposed to Ag X-rays. The mobility-lifetime product (µτ) of the electrons and holes estimated from the photocurrent measurements are (µτ) e ~ 3.6×10 -4 cm 2 /V and (µτ) h ~ 2.0 ×10 -4 cm 2 /V. Electronic structure calculations at the Density Functional Theory level indicate an indirect band gap and a relatively small effective mass for both electrons and holes. Based on the photoconductivity data, TlHgInS 3 is a potential material for radiation detection applications.

Na2Hg3M2S8 (M = Si, Ge, and Sn): New Infrared Nonlinear Optical Materials with Strong Second Harmonic Generation Effects and High Laser-Damage Thresholds

“…Developing new infrared (IR) light sources has become increasingly important in satisfying various practical applications. , An efficient approach to realize the output of IR laser is frequency-conversion technology. IR nonlinear optical (NLO) materials, as critical devices, are indispensable for the above technology. − Unfortunately, commercial IR NLO materials still exist a series of self-defects to hinder their wide application. − For that reason, exploration of the new IR NLO materials with excellent properties (broad IR transparency range, large second harmonic generation (SHG) response, and high damage resistance) is extremely urgent. − Recently, increasing attention has been focused on Hg ( d 10 element)-containing metal chalcogenides since the Hg cation has variable coordination numbers (2–4) with S atoms, and HgS is usually amenable to participate in the reaction while introducing alkali-metals into reaction system, which produce an efficient approach to design interesting crystal structures. − Several Hg-containing metal chalcogenides with excellent properties as promising IR NLO materials were discovered as yet. For instance, HgGa 2 S 4 crystallizes in tetragonal I4̅ space group with a “defect” chalcopyrite structure and has shown good application in high-power ultrafast laser system with large NLO coefficient ( d 36 = 34 pm/V) and high damage resistance. , BaHgS 2 belongs to NCS space group ( Pmc 2 1 ) with two different types of Hg atoms (HgS 4 tetrahedron and linear-like HgS 2 unit) in its structure and appears large SHG response ( d 33 = −59.7 pm/V) about five-times that of benchmark AgGaS 2 .…”

2D Magnetic Semiconductor Fe3GeTe2 with Few and Single Layers with a Greatly Enhanced Intrinsic Exchange Bias by Liquid-Phase Exfoliation

“…The macroscopic resistivity is more than 2 orders of magnitude higher than that of the FGT nanoflake, which may be caused by the abundant interfaces arising from lamellar stacking. Furthermore, the indistinct absorption band and relatively shallow slope of the absorption edge in UV−vis absorption spectra (Figure 3a) suggest an indirect transition, 93 and the band gap is found to be ∼1.75 eV according to a Tauc relation, 94 as shown in Figure 6e. The semiconductive properties of liquid-phase exfoliated FGT nanoflakse are different from the inherent cognition of a metallic FGT ferromagnet, 95,96 which imples that the oxidation in the surface layers changes the electronic structure of the system.…”

Revisiting two thiophosphate compounds constituting d0transition metal HfP2S6and d10transition metal α-Ag4P2S6as multifunctional materials for combining second harmonic generation response and photocurrent response

“…The photocurrent density of α-Ag 4 P 2 S 6 and β-Ag 4 P 2 S 6 is 165 nA cm −2 and 135 nA cm −2 , respectively. A comparison of photocurrent response among α-Ag 4 P 2 S 6 , β-Ag 4 P 2 S 6 and many previously reported sulfides is summarized in Table S2 † 51,114–124 . α-Ag 4 P 2 S 6 and β-Ag 4 P 2 S 6 show better photocurrent response than many sulfides such as BaCuSbS 3 (55 nA cm −2 ), 121 Cs 2 Ag 2 Zn 2 S 4 (50 nA cm −2 ), 122 Rb 2 Ba 3 Cu 2 Sb 2 S 10 (6 nA cm −2 ), 123 and TlHgInS 3 (0.35 nA cm −2 ).…”

“…α-Ag 4 P 2 S 6 and β-Ag 4 P 2 S 6 show better photocurrent response than many sulfides such as BaCuSbS 3 (55 nA cm −2 ), 121 Cs 2 Ag 2 Zn 2 S 4 (50 nA cm −2 ), 122 Rb 2 Ba 3 Cu 2 Sb 2 S 10 (6 nA cm −2 ), 123 and TlHgInS 3 (0.35 nA cm −2 ). 124 α-Ag 4 P 2 S 6 is a multifunctional material which combines moderate NLO properties and photocurrent response. The polymorphism study of α-Ag 4 P 2 S 6 and β-Ag 4 P 2 S 6 also demonstrates the rich structural chemistry of the ternary Ag–P–S system.…”