American Institute of Physics, Journal of Applied Physics, 3(110), p. 033103
DOI: 10.1063/1.3621143
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Three multijunctions consisting of La0.9Sr0.1MnO3−δ and LaAlO3−δ on Si substrate have been fabricated under different oxygen pressures by laser molecular beam epitaxy. They exhibit nonlinear and rectifying current-voltage characteristics and evident photocurrent response to He-Ne laser illumination. Experimental results indicate that the periodically stacked multijunction grown under lower oxygen pressure shows a better rectification behavior and a higher photocurrent. The photovoltaic responsivities of the multijunctions are enhanced greatly at reverse bias and are much higher than that of a similarly grown single p-n junction. Based on the band structure of the multilayers, a possible mechanism of the photovoltaic process was proposed. A high photovoltage responsivity of 168.6 mV/mW has been achieved at − 6 V bias; this demonstrates the potential of the present multijunction configuration for photodetectors operating at room temperature.