Characterization of electron-beam deposited SnS films: Processing, properties, and ohmic contacts

Abstract

Nanocrystalline tin sulfide (SnS) thin films were deposited by electron-beam evaporation at growth temperatures ranging from room temperature to 300 °C and characterized prior to and after annealing at 300 °C in high vacuum. X-ray diffraction and Raman spectroscopy results indicated that SnS films deposited at 100 and 200 °C contained predominately a mixture of orthorhombic α-SnS and cubic π-SnS phases, whereas only α-SnS was detected in SnS films deposited at 300 °C. Contacts with a range of work functions were deposited onto p-type α-SnS films. All of the contacts investigated (Ti/Au, Ru/Au, Ni/Au, and Au) were ohmic as-deposited and yielded average specific contact resistance values that decreased with increasing metal work function, suggesting that the barrier height has at least a partial dependence on the work functions of the metals. Annealing at 350 °C for 5 min in Ar reduced the specific contact resistance value for Ru/Au contacts, resulting in the lowest value (1.9 × 10−3 Ω cm2) of contacts investigated to SnS thin films.

Geometry-asymmetric photodetectors from metal–semiconductor–metal van der Waals heterostructures

“…2b and e. The SnS/metal junctions show semi-linear and/or linear I – V characteristics for different metals including Pt, Au, Ag, Al, In, and graphene, 44–50 which can be explained by tunnelling due to high carrier concentrations. Since the hole concentration of SnS is in the range of 10 17 –10 19 cm −3 and its bandgap is 1.12 eV, the TFE mechanism dominates the carrier transport across the SnS/metal junction, as shown in the inset of Fig.…”

Layer‐Controlled Low‐Power Tunneling Transistors Based on SnS Homojunction

“…Note that there is no real metallic source and drain contacts in the models, so that the effect of metal-SnS hybridization is not considered in this work. Experimentally, Ohmic contacts are detected for Ti/Au, Ru/Au, Ni/Au, Au, Ni, and Pd contact to as-prepared multilayer p-type SnS and SnS nanoribbons, [15,18,30] and these metal electrodes are commonly selected as ideal electrodes for 2D SnS electronics in practical. Three types of SnS homojunction TFETs are built with L g = 10 nm, including BL SnS source, ML SnS channel and drain (BL source SnS homojunction TFET); BL SnS drain and ML SnS source and channel (BL drain SnS homojunction TFET); BL SnS source and drain, and ML SnS channel (BL source&drain SnS homojunction TFET).…”

“…[9] Layered SnS has geometry and electronic features similar to BP. Large-scale multilayer or even monolayer [10,11] SnS have been synthesized in labs through various techniques like mechanical exfoliation, [12] physical vapor deposition, [11] liquid-metal synthesis, [10,13] pulsed laser deposition, [14] electron-beam evaporation, [15] and so on. Broad uses of SnS layers have been suggested for photoelectric devices, [13,14,16,17] transistors, [12,14,18,19] piezoelectric nanogenerators, [10] and so on.…”

Investigation of spray pyrolyzed cubic structured Cu doped SnS films

“…Recently, some studies have shown that doping of SnS with aluminum (Al), iron (Fe), indium (In), copper (Cu) and silver (Ag) can enhance its photovoltaic properties [8][9][10][11][12]. Doped and undoped SnS lms can be deposited by several techniques such as RF magnetron sputtering [8], vapor transport deposition (VTD) [13], e-beam evaporation [14], thermal evaporation [15], electrodeposition [10], chemical bath depositions [7], spray pyrolysis [12]. However, very few studies that investigate the effect of Cu doping on the physical properties of large cubic phase of SnS by spray pyrolysis exist in the literature.…”