Solar-driven
generators are an emerging power generation technology
due to the use of sunlight as a green and renewable energy source.
However, the complex, tedious, and costly fabrication processes impede
large-scale practical application. In this work, we demonstrate a
unique solar-thermal generator for efficient solar–thermal–electric
conversion to enable real-time, outdoor charging applications using
green solar energy. Our solar absorber comprises a cost-effective
layer of nanoscale carbon black powders/polyvinylidene fluoride (CB/PVDF)
mixture that can be easily sprayed onto the hot end of a commercial
thermoelectric device for large-scale fabrication of the solar generator.
The solar–thermal conversion of the CB/PVDF solar absorber
can be enhanced by designing hierarchical, micro/nano-sized porous
structures for better light penetration and utilization and using
an insulating sponge cover to promote heat localization and avert
potential environmental fluctuations. These design criteria are necessary
to achieve a stable and high electrical output (3.3 mW under 1 sun),
even under diverse operating conditions such as different ambient
temperatures (0–25 °C) and various sunlight intensities
(1–7 sun). As a proof-of-concept application, our generators
can be connected in series/parallel and further integrated with a
voltage conversion module to enable the efficient and instantaneous
charging of modern electronic devices using green solar energy, notably
at a charging rate of about 5% per hour. Our unique design is anticipated
to expedite the development of an efficient, portable solar generator
with the aim to decentralize green power generation, which is beneficial
in remote places that do not have access to the electrical grid.