EXCITONS IN WS2 FILMS - PRESSURE AND TEMPERATURE EFFECTS

A technique for producing thin film samples WS2 is reported. Exciton peak positions are measured as a function of hydrostatic pressure to 3500 atm at 90 K and temperatures in the range 90 to 300 K. Values for (∂E/∂P)T for the A‐ and B‐peaks are 5.9 × 10−6 and 7.2 × 10−6 eV/atm, respectively. Peak C shifts 0.3 × 10−6 eV/atm, while values of (∂E/∂T)P are −1.8 × 10−4, −2.8 × 10−4, and −0.3 × 10−4 eV/K for peaks A, B, and C, respectively. The value of (∂E/∂T)V is estimated at 1 × 10−4 eV/K. A comparison of these results with those for MoS2 is made, and comments are made concerning the nature of the band structure of WS2. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA