Thermoradiative Diodes Using Black Phosphorus van der Waals Materials

ABSTRACT The high radiative efficiencies and strong absorption coefficients of van der Waals materials position them well for optoelectronic power generation via radiative exchange. These materials have been investigated for use in solar cells, however, their use in thermoradiative and thermophotovoltaic applications in the mid‐infrared remains unexplored. We fabricate a black phosphorus ()/molybdenum disulfide () van der Waals heterojunction diode and use it in both thermoradiative and thermophotovoltaic operation modes. Open circuit voltage and short circuit current measurements taken as a function of temperature difference between the device and its environment, show the device can effectively generate power in both regimes. A net power density of is achieved at (thermoradiative), and at (thermophotovoltaic). This represents the first demonstration of thermoradiative power generation using van der Waals materials. Optoelectronic modeling further indicates that the performance is primarily limited by optical out‐coupling and external quantum efficiency. By addressing these, the short circuit current density could be increased by up to three orders of magnitude, corresponding to an approximate six orders of magnitude increase in power density.