Influence of substrate temperature on the deposition of the homostructure SnO2:Sb/SnO2:Er via sol-gel dip-coating

SnO2 thin films doped with Sb5+ and Er3+ were deposited by sol-gel-dip-coating forming the homostructure SnO2:Sb/SnO2:Er, between aluminum contacts. The films were deposited on glass substrates at room temperature and 90 degrees C. The homostructure showed capacitive behavior as obtained from cyclic voltammetry, and the sample deposited with heated substrate at 90 degrees C showed a curve similar to a switchable ferroelectric diode, mainly for low scan rates. Heated substrates also lead to device higher transmittance in the near infrared, related to lower electron concentration, but the improvement in the sample quality leads to higher mobility, compensating the lower electron concentration, causing an overall effect of higher conductivity.