Crystal shape engineering and studies on the performance of vapour deposited InSe platelets

The influence of growth conditions on the morphology of stoichiometric indium monoselenide (InSe) crystals has been explored. Crystalline habits such as microfibres, needles, platelets and spherulites were obtained from physical vapour deposition by optimizing supersaturation, which sturdily depends on the temperature difference between charge (T-C) and substrate (T-S) zones a dagger T, (= T-C - T-S). Morphology and growth mechanism were investigated with the aid of scanning electron microscopy and high-resolution transmission electron microscopy, which justified the layer by layer addition of atoms as per the Kossel-Stranski-Volmer model. Thermogravimetric measurements revealed the stability of InSe, confirming its melting point, M.P. = 611 A degrees C, which reflects the formation of monophase. The mobility and carrier concentration calculated from the Hall effect experiment are found to be 11.14 cm(2) V-1 s(-1) and 1.52 x 10(20) cm(-3) respectively. Furthermore, optical characterizations such as UV-Vis-NIR and photoluminescence spectrometric analysis established the value of band gap as 1.45 eV, manifesting the versatility of the grown semiconducting platelets for photovoltaic applications.