Integrated silicon-based spectral reshaping intermediate structures for high performance solar thermophotovoltaics

•The spectral reshaping intermediate structure on silicon substrate with simple fabrication process.•The hierarchical Si NW absorber exhibits an excellent optical absorption performance from 220 nm to 1100 nm and a lower emittance above 1100 nm.•The Si-W-SiN/SiNO multilayer emitter shows a selective narrowband absorption (i.e., emission) peak in the target wavelength and low thermal radiation loss in long wave range.•The overall efficiency of the whole STPV system is precisely optimized by varying emitter parameters and system parameters.•At achievable light concentration intensity of 1000, the STPV system efficiency can exceed 29% using this integrated silicon-based intermediate structure.