Fig. 1. Schematic of the BANE structure and the geometric parameters of one unit cell. The BANE film is a three-layered structure consisting of lossy TiN cross features on top of a lossless AlN layer and a substrate of TiN.

Fig. 2. (a) Polarization-averaged normalized absorption spectra of a BANE structure: L=0.28  μm; W=0.11  μm; P=0.4  μm; H1=0.08  μm; H2=0.03  μm; H3=0.1  μm for various incidence angles. (b) Radiation spectra of blackbody and the BANE structure at 800, 1500, and 2000 K. (c) Normalized absorption spectra for varying L of 0.24, 0.26, 0.28, 0.3, and 0.32 μm. Normalized absorption spectrum as a function of width of cross structure (W in Fig. 1) in (d) and height of cross structure (H1 in Fig. 1) in (e). (f) Normalized reflection (black line) transmission (red line) and absorption (blue line) spectra of 0.1 μm TiN film.

Fig. 3. (a) Field distributions. (b) Resonance wavelength of 2 μm. (c), (d) Nonresonance wavelength of 1.25 μm for the BANE structure in Fig. 2(a) at normal incidence. (a) and (c) Electric field. (b) and (d) Magnetic field.

Fig. 4. (a) Artificial absorption/emission spectrum ϵart(λ). (b) Maximum overall PCE as a function of bw1 and bw3.

Fig. 5. Contours of (a) ultimate efficiency, U, (b) recombination efficiency, ν, (c) impedance matching factor, m, (d) overall STPV efficiency, η.