Photoluminescence and differential reflection measurements are performed on exfoliated single layer and bulk MoS2, then compared to measurements taken on stacked thin films of SnSe and MoSe2 grown via sequential physical vapor deposition. We find the exciton absorption peaks present in the exfoliated samples are absent in the stacked (SnSe) (MoSe2) samples. Preliminary band gap measurements of single layer MoS2 using an alternate technique, second harmonic generation enhancement, are also presented.