Clean and abundant solar energy has been intensively explored as an alternative to traditional fossil fuels over the past decades [1]. As a key component, absorbers that convert solar radiation into thermal energy greatly affect the performance of various solar thermal systems. An ideal solar absorber should possess an absorptance of unity in the solar spectrum covering UV, visible and near infrared (NIR) to convert most solar radiation into heat, along with zero emittance in the mid-IR regime to minimize energy loss from spontaneous thermal radiation [2]. This spectral selectivity is vital for solar thermal absorbers to achieve high solar-to-heat conversion efficiency. In addition, angular and polarization independence is highly desired for efficient solar absorbers considering the random nature of solar radiation. Excellent thermal stability is also crucial for ensuring solar absorbers to operate properly and efficiently convert solar energy to heat at elevated temperatures over time. Commercially, TiNOX [3] and Pyromark [4] have been used as solar absorbers for low- to high-temperature applications. Spectrally-selective TiNOX coatings could absorb 95% of incident solar radiation and emit only 4% thermal radiation, but its performance is optimal only around 100 °C. On the other hand, Pyromark exhibits a near-normal absorptance above 0.95 at high temperatures of around 650 °C, but its thermal emittance is also as high as 0.8. Unfortunately, efficient solar absorbers with both spectral selectivity and high-temperature compatibility are still lacking.