Magnetical and electrical tuning of transient photovoltaic effects in manganite-based heterojunctions.

Magnetically and bias current tunable transient photovoltaic (TPV) responses have been investigated in a manganite-based heterojunction composed of a La2/3Ca1/3MnO3 film and an n-type Si substrate at ambient temperature. Under irradiation of 248 nm pulsed laser with 20 ns duration the TPV peak values can be modulated in a range of -125 to 138 mV when the applied magnetic field perpendicular to the interface changes from -6.4 to + 6.4 kOe, and the relative variations (TPV(H) - TPV(0))/TPV(0) reach up to about 1000%. In addition, TPV responses can be also affected by bias current, and the photoresponse peaks change from positive to negative with the currents from -350 to 350 μA. These results indicate that the manganite-based heterojunction can be used for magnetically and electrically tunable ultraviolet photodetectors.