This isn't about sunlight, but about putting this with a furnace or something else generating heat.
Regarding the article posted here (and since a drone with a furnace is not feasible) I went with solar.
The original paper says "unmanned vehicles" (no aerial) and has a reference [0] to "unmanned undersea vehicles".
[0] https://www.pnas.org/content/early/2019/07/15/1903001116#ref...
100 megawatts is followed by "[providing] electricity for 36,000 homes."
The original paper does not mention lightweight aerial vehicles as an application, but a drone is mentioned in the title (and shown in the top image) of the article.
Applications mentioned in the paper are: hybrid cars, unmanned vehicles, deep-space probes, energy storage, enabling efficient cogeneration systems for heat and electricity.
(A less-misleading title might even be: "New thermophotovoltaic engine for deep-space probes")