Extended Data Fig. 2: Air-bridge cell profilometry.
From: Near-perfect photon utilization in an air-bridge thermophotovoltaic cell
a, b, Schematic of an air-bridge TPV cell after the substrate removal and before the top contact grid lines patterning (a) and the top surface profilometry measurement of the cell in a (b). The designed air cavity thickness is 700 nm. TPV epitaxial layers bow slightly downward by about 100 nm (~0.1% of the lateral span of each air cavity), resulting in an actual air cavity thickness of ~600 nm in the air-bridge cell.
