Heterojunction thermophotovoltaic cell with Ge (germanium) substrate

The invention relates to a heterojunction thermophotovoltaic cell with a Ge (germanium) substrate. The heterojunction thermophotovoltaic cell comprises the Ge substrate serving as a base region, an emitting cell, an upper electrode contact layer and an upper electrode are arranged on the Ge substrate from bottom to top, a lower electrode is arranged below the Ge substrate, a p-Ge layer narrow in a band gap serves as the Ge substrate, and an n-GaxInyP layer wide in the band gap serves as the emitting region. The n-GaxInyP layer wide in the band gap and accurately adjustable in the ratio of Ga (gallium) to In (indium) is adopted to serve as the emitting region, the p-Ge substrate narrow in the band gap is adopted to serve as the base region, a heterojunction structure with accurately matched crystal lattices of the emitting region and the base region is formed, interface combination of the GaxInyP/Ge is reduced, light absorption of the emitting region of the wide-band-gap emitting region is decreased, light absorption of the base region is increased, recombination of photon-generated carriers in the n-shaped emitting region and on the surface of the n-shaped emitting region is reduced, collection efficiency of the photon-generated carriers is improved, and photoelectric conversion efficiency of the cell is improved effectively.