Interstitial Doping of SnO₂ Film with Li for Indium-Free Transparent Conductor

SnO2 films exhibit significant potential as cost-effective and high electron mobility substitutes for In2O3 films. In this study, Li is incorporated into the interstitial site of the SnO2 lattice resulting in an exceptionally low resistivity of 2.028 x 10(-3 )omega & sdot;cm along with a high carrier concentration of 1.398 x 10(20) cm(-3 )and carrier mobility of 22.02 cm2/V & sdot;s. Intriguingly, Li i readily forms in amorphous structures but faces challenges in crystalline formations. Furthermore, it has been experimentally confirmed that Li i acts as a shallow donor in SnO2 with an ionization energy Delta E-D1 of -0.4 eV, indicating spontaneous occurrence of Li i ionization.