Lu, YueruiLal, Amit2026-06-202026-06-20978-1-4614-8168-3978-1-4614-8169-0Bibtex:lu2013applicationsORCID:/0000-0001-6131-3906/work/218072686https://hdl.handle.net/1885/733811701Nanostructured silicon thin-film solar cells are promising, due to the strongly enhanced light trapping, high carrier collection efficiency, and potential low cost. Ordered nanostructure arrays, with large-area controllable spacing, orientation, and size, are critical for reliable light-trapping and high-efficiency solar cells. Available top–down lithography approaches to fabricate large-area ordered nanostructure arrays are challenging due to the requirement of both high lithography resolution and high throughput. Here, a novel ordered silicon nano-conical-frustum array structure, exhibiting an impressive absorbance of ~99% (upper bound) over wavelengths 400–1100 nm by a thickness of only 5μm, is realized by our recently reported technique self-powered parallel electron lithography that has high throughput and high resolution. High-efficiency (up to 10.8 %) solar cells are demonstrated, using these ordered ultrathin silicon nano-conical-frustum arrays. Moreover, these ordered nano-structures have been successfully integrated into nano-electro-mechanical system (NEMS), enabling high-efficiency and broad-band optical actuation for NEMS devices. The first-ever nanopillar membrane acoustic speaker, using nano-scale photonic crystal optical absorbers for thermo-mechanical excitation of speaker membrane, is demonstrated.22en201310.1007/978-1-4614-8169-0_485103637391