Complementary NIR absorption of ZnSe induced by multiple PbSe submonolayers by vacuum deposition technique

The paper reports the possibilities to utilize the full solar spectrum (UV-NIR) by combining two different materials which have wide transparency over visible and NIR region. Simple vacuum deposition was preferred to produce ZnSe thin films with multiple 2D PbSe submonolayers (ML). Cross sectional TEM image proves the PbSe ML are well in order and has good periodicity at the interfaces of ZnSe layers which exactly matches with SAXS profile. Optical absorption of ZnSe shows the absorption in visible region while insertion of PbSe ML lead to enhancement of absorption in NIR region. A Photoluminescence spectrum of ZnSe-PbSe reveals the emission at NIR region which supports the absorption studies. In addition, Raman scattering was performed to study the presence of strain in the ZnSe layers.