Quantum electronic discussion was made on metal/SrTiO3 hetero-structure to obtain the design concept for high-temperature photo-electronic devices using SrTiO3. The current density ratios were calculated between tunneling and thermionic emission component across the hetero-interface, which indicates how much dopant concentration is required for ohmic or Schottky contact. WKB approximation and Gamow transmission coefficient were used in calculation of the tunneling coefficient. The calculated results show good agreement with experimental results. The possibility of high-temperature photo-electronic devices using SrTiO3 was shown both in theoretical and experimental approach.