Abstract: Gamma phase (γ) Bi2 Sn2 O7 was synthesized by hydrothermal method and its photoelectric response in visible light was investigated .The structure and photoelectric response properties were characterized by X-ray diffraction and surface photovoltage spectroscopy . The results show the as-prepared Bi2 Sn2 O7 presents a presents a gamma (γ) phase cubic structure and has an optical band gap (2.67 eV) measured by absorption spectrum , which is narrower than that of α-Bi2O3 (2.85 eV).The photoelectric response of Bi 2 Sn2 O7 in visible light area displays its advantage compared with α-Bi2 O3 . Meanwhile , it has strong response under the applied voltage .

Key words: Gamma phase (γ) Bi2 Sn2 O7 was synthesized by hydrothermal method and its photoelectric response in visible light was investigated .The structure and photoelectric response properties were characterized by X-ray diffraction and surface photovoltage spectroscopy . The results show the as-prepared Bi2 Sn2 O7 presents a presents a gamma (γ) phase cubic structure and has an optical band gap (2.67 eV) measured by absorption spectrum , which is narrower than that of α-Bi2O3 (2.85 eV).The photoelectric response of Bi 2 Sn2 O7 in visible light area displays its advantage compared with α-Bi2 O3 . Meanwhile , it has strong response under the applied voltage .