Growth and characterization of LiInSe2 single crystals

Non-stoichiometry and point native defects in non-oxide non-linear optical large single crystals: advantages and problems

“…68 The crystal compositions determined by ICP OES as Li 1.04 In 1.10 Se 2 , Li 0.99 In 1.02 Se 2 , and Li 1 In 1.06 Se 2 well correlate with color varying from deep red to ruby-colored and to yellow and with the E g values being 2.01, 2.15, and 2.83 eV, respectively. 67 The convergence of the direct and indirect results identifying non-stoichiometry of LiMX 2 crystals increases their reliability and gives additional insight into the understanding of non-stoichiometry.…”

“…In search of effective indicators of defects, many works were performed. 3,63–68 In LISe crystals grown by the B technique, antisite defects of In Li and Li In were identified experimentally via color, actual composition and band gap in combination with theoretical calculation. 63 Herein, even with seemingly optimal technology, red as-grown crystals were defective and converted to yellow on annealing in the presence of LISe polycrystalline material.…”

“…3 In contrast, for minimizing defects in LGSe crystals grown by the modified B technique, annealing in Li metal vapor was used that implies any Li deficiency. 67…”

Electronic structure and transport properties of TlInSe2 and Tl0·5Li0·5InSe2

“…2d). against competing phases remains to be demonstrated experimentally, the successful synthesis of large single crystals of LiInSe 2 [26,27] and thin films of Cu 0.5 Li 0.5 InSe 2 [28] suggests that the thermodynamic stability of Tl 0.5 Li 0.5 InSe 2 is plausible. Our calculated formation energy per atom of TlInSe 2 and Tl 0.5 Li 0.5 InSe 2 are -0.398 eV and -0.475 eV, respectively.…”

“…The latter compound is known to be a wide-band gap semiconductor with a gap energy E gap = 2.85 eV [23] as opposed to TlInSe 2 where E gap =1.1-1.4 eV [24][25]. Although the phase stability of the hypothetical compound Tl 0.5 Li 0.5 InSe 2 is yet to be demonstrated the successful synthesis of large single crystals of LiInSe 2 [26,27] and thin films of Cu 0.5 Li 0.5 InSe 2 [28] suggests that thermodynamic stability of Tl 0.5 Li 0.5 InSe 2 is plausible. Our DFT calculations allow us to evaluate the electronic density of states and transport properties for 50% Li-substitution where a rigid-band model is inappropriate.…”