Pressure-induced structural and electronic transitions, metallization, and enhanced visible-light responsiveness in layered rhenium disulphide

Abstract

and zhaoys@sustc.edu.cn † Supplemental Materials available: Detailed sample characterizations (including crystal structure and pressure-dependence of lattice parameters of layered ReS 2 , enthalpy curve of ReS 2 as a function of pressure, schematics of electrical resistance measurements in DAC, and electrical resistance results using large volume press).‡ Equal contribution. ABSTRACT: Triclinic rhenium disulphide (ReS 2 ) is a promising candidate for postsilicon electronics because of its unique optic-electronic properties. The electrical and optical properties of ReS 2 under high pressure, however, remain unclear. Here we present a joint experimental and theoretical study on the structure, electronic and vibrational properties, and visible-light responses of ReS 2 up to 50 GPa. There is a direct to indirect band gap transition in 1T-ReS 2 under low pressure regime up to 5GPa. Upon further compression, 1T-ReS 2 undergoes a structural transition to distorted-1T′ phase at 7.7 GPa, followed by the isostructural metallization at 38.5GPa. Both in situ Raman spectrum and electronic structure analysis reveal that interlayer sulphur-sulphur interaction is greatly enhanced during compression, leading to the remarkable modifications on the electronic properties observed in our subsequent experimental measurements, such as band gap closure and enhanced photo-responsiveness. This study demonstrates the critical role of pressure in tuning materials properties and the potential usage of layered ReS 2 for pressure-responsive optoelectronic applications.

Structural and High-Pressure Properties of Rheniite (ReS2) and (Re,Mo)S2

“…The appearance of these reflections can be attributed to the 1T to 1T' phase transition. Noteworthy, the low phase-transition pressure value found in this work agrees well with previous DFT calculations [19,22,24]. With regard to experimental determinations, our results seem to confirm the observations of Ref.…”

“…These values are in excellent agreement with the PBE+D3 calculations (BM-3 fit, see Table 1) and also with the recent work by Saha et al [23], who reported a similar experimental bulk modulus (B 0 = 44(2) GPa), although with a much lower first derivative (B' = 1.6(3)). In contrast, other previous works reported much lower B 0 values of 23 GPa [21] and 35.6 GPa [22]. The latter is in very good agreement with the BM-4 fit to our PBE+D3 data, while our experimental bulk modulus obtained with a BM-4 is slightly larger (41.3(2) GPa, see Table 1).…”

“…Natural TMDCs include rheniite (ReS 2 ), molybdenite (MoS 2 ), tungstenite (WS 2 ), or drysdallite (Mo(Se,S) 2 ). Their synthetic counterparts are currently around 6-8 GPa [23], in agreement with the HP-XRD studies, which report values around 6-11.3 GPa [21][22][23]. However, it is worth noting that the previous Raman-scattering studies only considered high-frequency modes related to intralayer vibrations rather than low-frequency interlayer modes, which should be more sensitive to the layer stacking configuration.…”

“…[26], where the structural phase transition was found around 2.5 GPa by means of Raman spectroscopy. In contrast, most experimental works have reported much larger phase transitions, typically above 5 GPa and up to 15 GPa [21][22][23]27]. The present results allow us to conclude that the onset of the phase transition for 1T-ReS 2 is as low as~2 GPa.…”

“…DFT calculations have been widely used to understand, among others, the optical [27], electrical [19] and structural [22] properties of ReS 2 . DFT studies published so far have shown to be highly dependent on the particular functional used, predicting a phase transition onset between 0.1 GPa and 3 GPa, [19,22,24] far from most experimental values, around 6-11.3 GPa [21][22][23]. The poor agreement between experimental and theoretical results highlights the importance of additional experimental and theoretical works to better constrain the pressure behavior of ReS 2 .…”