Solar thermophotovoltaic (STPV) systems convert sunlight into electricity via thermal radiation. The efficiency of this process depends critically on both the selective absorber and the selective emitter, which are controlled by both the materials and the photonic design. For high concentration solar TPV applications, 2D photonic crystals (PhCs) made of refractory metals such as tungsten have demonstrated promising results. For even higher performance, we propose two photonic crystal-based designs to both collect solar heat and reradiate above-gap photons. First, a PhC selective structure (IPSS), which combines 2D photonic crystals and filters into a single device. Second, an Er-Yb-Tm co-doped fused silica coated with a 17-bilayer structure also offers significant selectivity with greater ease of fabrication. Finite difference time domain (FDTD) and rigorous coupled wave analysis (RCWA) simulations show that both can significantly suppress sub-bandgap photons. This increases sunlight-to-electricity conversion for photonic crystal-based emitters above 24.3% at 100 suns concentration or 27% at 1000 suns concentration using a Ga0.42In0.58As PV diode with a bandgap of 0.7 eV (nearly lattice-matched to InP).