1.64
1.66
1.68
1.7
1.72
1.74
1.76
1.78
-6
-4
-2
0
2
4
6
photon energy (eV)
gate voltage (V)
Exciton to trion crossover in reflectance contrast
-0.4
-0.2
0
0.2
0.4
dR/R