We present a low-cost and scalable approach for the synthesis of wafer-scale InAs nanowire (NW) arrays on photolithographically patterned, reusable Si wafers using a localized selfassembly (LSA) epitaxial growth technique. Conventional i-line lithography is used to define arrays of 500 nm diameter pores through 50 nm thick SiO 2 layers, which serve as the LSA mask. A two-step, flowrate-modulated growth sequence is implemented to optimize selective-area self-assembly of NW arrays with over 80% yield and excellent control over the placement of one NW, with a mean diameter of 130 nm, inside each 500 nm pore. As-grown NW arrays are delaminated from the growth substrate, enabling fabrication of flexible membrane devices as well as reuse of Si wafers and growth masks while preserving the template pattern fidelity. Reuse of Si substrates for III−V epitaxy is demonstrated with and without pre-growth substrate restoration treatments. In both cases, the yield of NWs on reused wafers is comparable to that achieved in the original growth run. Without substrate restoration procedures, the remnant base segments of NWs on parent wafers act as preferential sites for regrowth of vertical NWs. Transmission electron microscopy analysis reveals that the InAs lattice is coherently extended from the remnant NW base segments during regrowth. The delaminated InAs NW arrays are transferred to carrier wafers for the fabrication of substrate-free photodetectors through the use of an anchoring procedure, which preserves the original NW position and orientation. Under broadband illumination, the NW array-based photodetectors produce a photo-to-dark current ratio of 10 2 , demonstrating the utility of the fabrication procedure employed. This work establishes a low-cost route toward III−V semiconductor-based flexible optoelectronics via LSA epitaxial growth of NW arrays on reusable Si wafers.
We present a novel, highly non-degenerate, heralded visible-telecom photon-pair source using an integrated system of nonlinear waveguides and photonic circuits. Thermo-optic modulation of the telecom single-photon-state is demonstrated for deployable quantum communication/networking systems.
We demonstrate integration of periodically-poled KTiOPO4 (PPKTP) waveguides generating visible-telecom wavelength photon pairs with Photonic Integrated Circuits, bridging visibly-accessed quantum technologies and telecom infrastructure. High pair rates, heralding and telecom-filterless operation are demonstrated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.