01611nas a2200217 4500008004100000022001400041245006000055210005900115260007100174300001400245490000600259520089400265653002201159653002201181653002301203653001901226653000801245100002301253700002401276856009301300 2014 eng d a1944-824400aTemperature Dependent Phonon Shifts in Single-Layer WS20 aTemperature Dependent Phonon Shifts in SingleLayer WS2 a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN a1158-11630 v63 a

Atomically thin two-dimensional tungsten disulfide (WS2) sheets have attracted much attention due to their potential for future nanoelectronic device applications. We report first experimental investigation on temperature dependent Raman spectra of single-layer WS2 prepared using micromechanical exfoliation. Our temperature dependent Raman spectroscopy results shows that the E-2g(1) and A(1g) modes of single-layer WS2 soften as temperature increases from 77 to 623 K. The calculated temperature coefficients of the frequencies of 2LA(M), E-2g(1), A(1g), and A(1g)(M) + LA(M) modes of single-layer WS2 were observed to be -0.008, -0.006, -0.006, and -0.01 cm(-1) K-1, respectively. The results were explained in terms of a double resonance process which is active in atomically thin nanosheet. This process can also be largely applicable in other emerging single-layer materials.

10alayered materials10aphonon vibrations10aRaman spectroscopy10athermal effect10aWS21 aThripuranthaka, M.1 aLate, Dattatray, J. uhttp://library.ncl.res.in/content/temperature-dependent-phonon-shifts-single-layer-ws2-001831nas a2200205 4500008004100000022001400041245007000055210006900125260007100194300001400265490000600279520110600285653002101391653002201412653002201434653002301456653001901479100002401498856010301522 2015 eng d a1944-824400aTemperature dependent phonon shifts in few-layer black phosphorus0 aTemperature dependent phonon shifts in fewlayer black phosphorus a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR a5857-58620 v73 a

Atomically thin two-dimensional (2D) sheets of black phosphorus have attracted much attention due to their potential for future nanoelectronic and photonics device applications. Present investigations deal with the temperature dependent phonon shifts in a few-layer black phosphorus nanosheet sample prepared using micromechanical exfoliation on a 300 nm SiO2/Si substrate. The temperature dependent Raman spectroscopy experiments were carried out on a few-layer black phosphorus sample, which depicts softening of Ag-1 B-2g, and A(g)(2) modes as temperature increases from 77 to 673 K. The calculated temperature coefficients for Ag-1, B-2g, and A(g)(2) modes of the few-layer black phosphorus nanosheet sample were observed to be -0.01, -0.013, and -0.014 cm(-1) K-1, respectively. The temperature dependent softening modes of black phosphorus results were explained on the basis of a double resonance process which is more active in an atomically thin sample. This process can also be fundamentally pertinent in other promising and emerging 2D ultrathin layer and heterostructured materials.

10ablack phosphorus10alayered materials10aphonon vibrations10aRaman spectroscopy10athermal effect1 aLate, Dattatray, J. uhttp://library.ncl.res.in/content/temperature-dependent-phonon-shifts-few-layer-black-phosphorus-002553nas a2200325 4500008004100000022001400041245010200055210006900157260007100226300001600297490000600313520142000319653002201739653002201761653002301783653001901806653002101825653002001846100002201866700002301888700002001911700002201931700002001953700002301973700002401996700003102020700003002051700002402081856012202105 2015 eng d a1944-824400aTemperature-dependent raman spectroscopy of titanium trisulfide (TiS3) nanoribbons and nanosheets0 aTemperaturedependent raman spectroscopy of titanium trisulfide T a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV a24185-241900 v73 a

Titanium trisulfide (TiS3) has recently attracted the interest of the 2D community because it presents a direct bandgap of similar to 1.0 eV, shows remarkable photoresponse, and has a predicted carrier mobility up to 10000 cm(2) V-1 s(-1). However, a study of the vibrational properties of TiS3, relevant to understanding the electron-phonon interaction that can be the main mechanism limiting the charge carrier mobility, is still lacking. In this work, we take the first steps to study the vibrational properties of TiS3 through temperature-dependent Raman spectroscopy measurements of TiS3 nanoribbons and nanosheets. Our investigation shows that all the Raman modes linearly soften (red shift) as the temperature increases from 88 to 570 K due to anharmonic vibrations of the lattice, which also includes contributions from the lattice thermal expansion. This softening with the temperature of the TiS3 modes is more pronounced than that observed in other 2D semiconductors, such as MoS2, MoSe2, WSe2, and black phosphorus (BP). This marked temperature dependence of the Raman spectra could be exploited to determine the temperature of TiS3 nanodevices by using Raman spectroscopy as a noninvasive and local thermal probe. Interestingly, the TiS3 nanosheets show a stronger temperature dependence of the Raman modes than the nanoribbons, which we attribute to lower interlayer coupling in the nanosheets.

10a2D semiconductors10alayered materials10aRaman spectroscopy10athermal effect10aTiS3 nanoribbons10aTiS3 nanosheets1 aPawbake, Amit, S.1 aIsland, Joshua, O.1 aFlores, Eduardo1 aAres, Jose, Ramon1 aSanchez, Carlos1 aFerrer, Isabel, J.1 aJadkar, Sandesh, R.1 avan der Zant, Herre, S. J.1 aCastellanos-Gomez, Andres1 aLate, Dattatray, J. uhttp://library.ncl.res.in/content/temperature-dependent-raman-spectroscopy-titanium-trisulfide-tis3-nanoribbons-and-001900nas a2200205 4500008004100000022001400041245007600055210006900131260000800200300001100208490000600219520124400225653002101469653001001490653002101500653002301521653001901544100002401563856010701587 2016 eng d a2352-940700aTemperature-dependent phonon shifts in atomically thin MoTe2 nanosheets0 aTemperaturedependent phonon shifts in atomically thin MoTe2 nano cDEC a98-1020 v53 a

The present investigations deal with temperature-dependent Raman spectroscopy of bi-layer and few-layer molybdenum telluride (MoTe2) nanosheets prepared by micromechanical exfoliation method on a 300 nm SiO2/Si substrate. The temperature-dependent Raman spectroscopy was carried out using 633 nm laser excitation over the wider temperature range of 123-523 K. The temperature-dependent study illustrates the softening of A(1g), E-2g(1), and B-2g modes as temperature increases from 123 K to 523 K. The calculated temperature coefficients for A(1g), E-2g(1) and B-2g modes of the bi-layer MoTe2, nanosheet sample were found to be -0.00911 cm(-1) K-1, -0.01297 cm(-1) K-1 and -0.0159 cm(-1) K-1,respectively. For few-layer MoTe2 nanosheet sample, the temperature coefficient values were found to be -0.0113 cm(-1) K-1 (A(1g)), -0.0129 cm(-1) K-1 (E-2g(1)) and -0.0149 cm(-1) K-1 (B-2g), respectively. The present work highlights the temperature-dependent lattice vibration consequence of 2D MoTe2 nanosheet, which can be fundamentally pertinent in other promising and emerging 2D ultrathin layer and heterostructured materials to be used in future optoelectronic and nanoelectronic devices. (C) 2016 Elsevier Ltd. All rights reserved.

10aLayered material10aMoTe210aPhonon vibration10aRaman spectroscopy10athermal effect1 aLate, Dattatray, J. uhttp://library.ncl.res.in/content/temperature-dependent-phonon-shifts-atomically-thin-mote2-nanosheets01726nas a2200217 4500008004100000022001400041245011800055210006900173260000900242300001200251490000700263520099200270653001501262653001001277653002301287653001101310653001901321100002401340700002401364856012001388 2019 eng d a2190-428600aTemperature-dependent Raman spectroscopy and sensor applications of PtSe2 nanosheets synthesized by wet chemistry0 aTemperaturedependent Raman spectroscopy and sensor applications  cFEB  a467-4740 v103 a

We report on a wet chemistry method used to grow PtSe2 nanosheets followed by thermal annealing. The SEM and TEM analysis confirms the formation of PtSe2 nanosheets. Furthermore, XRD, Raman, XPS and SAED patterns were used to analyze the crystal structure and to confirm the formation of the PtSe2 phase. The temperature-dependent Raman spectroscopy investigations were carried out on PtSe2 nanosheets deposited on Si substrates in the temperature range 100-506 K. The shifts in Raman active E-g and A(1g) modes as a function of temperature were monitored. The temperature coefficient for both modes was calculated and was found to match well with the reported 2D transition metal dichalcogenides. A PtSe2 nanosheet-based sensor device was tested for its applicability as a humidity sensor and photodetector. The humidity sensor based on PtSe2 nanosheets showed an excellent recovery time of approximate to 5 s, indicating the great potential of PtSe2 for future sensor devices.

10ananosheets10aPtSe210aRaman spectroscopy10aSensor10athermal effect1 aPawar, Mahendra, S.1 aLate, Dattatray, J. uhttp://library.ncl.res.in/content/temperature-dependent-raman-spectroscopy-and-sensor-applications-ptse2-nanosheets