Material development for thin-film transistors

Graduation date: 2015The focus of this thesis is developing materials for thin-film transistors (TFTs).\ud Cu₃SbS₄ is explored as p-channel layer. Cu₃SbS₄ TFTs show p-type, depletion-mode\ud behavior with a small amount of gate-controlled modulation of the channel conductance.\ud This behavior is consistent with Hall measurements indicating a mobility of\ud 17 cm²V⁻¹s⁻¹ and hole carrier concentration of 10¹⁷ cm⁻³. Simulations employing\ud the comprehensive depletion-mode model (CDMM) are used to extract TFT channel\ud interface and bulk mobility, along with carrier concentration. The extracted values\ud from CDMM simulations are in close agreement with Hall-effect measurements of\ud carrier concentration and TFT incremental mobility.\ud TFTs are fabricated employing solution-processed thin films spin-coated with\ud electrochemically prepared solutions. Dual active-layer TFTs utilizing solution-processed\ud IZTO-IGZO active layers demonstrated the highest average mobility, exceeding that\ud of control sputtered IGZO TFTs.\ud Sputtered IGZO TFTs are studied using solution-processed Al₂O₃ and LaAlO₃\ud gate insulator layers. The solution-processed Al₂O₃ gate exhibits high subthreshold\ud swing compared to employing a thermally grown SiO₂ gate insulator layer