Novel nanoscale transfer printing technique for precise positioning of nanowire lasers

Semiconductor nanowires, with lasing emission at room temperature, can be transferred in a controlled way to specific locations on diverse substrates and organized into bespoke spatial patterns

Sub-micron-accuracy automated position and rotation registration method for transferred devices

We demonstrate a high accuracy and throughput automated method for the spatial registration of micron-scale devices on planar chips. The system is used to assess the yield, spatial pitch and rotation of mass transfer-printed membrane devices (here micro-LEDs for illustration) using simple optical microscopy tools

Transfer printing of semiconductor nanowire lasers

The authors review their work on the accurate positioning of semiconductor nanowire lasers by means of nanoscale Transfer Printing (nano-TP). Using this hybrid nanofabrication technique, indium phosphide (InP) NWs are successfully integrated at selected locations onto heterogeneous surfaces with high positioning accuracy. Moreover, we show that NW lasers can also be organised to form bespoke spatial patterns, including 1- or 2-Dimensional arrays, or complex configurations with defined number of NWs and controlled separation between them. Besides, our nano-TP technique also permits the integration of NWs with different dimensions in a single system. Notably, the nano-TP fabrication protocols do not affect the optical or structural properties of the NWs and they retain their room-temperature lasing emission after their positioning onto all investigated receiving surfaces. This developed nano-TP technique offers therefore new exciting prospects for the fabrication of hybrid bespoke nanophotonic systems using NW lasers as building blocks

Transfer printing of semiconductor nanowires with lasing emission for controllable nanophotonic device fabrication

Accurate positioning and organization of Indium Phosphide (InP) Nanowires (NW) with lasing emission at room temperature is achieved using a nanoscale Transfer Printing (TP) technique. The NWs retained their lasing emission after their transfer to targeted locations on different receiving substrates (e.g. polymers, silica and metal surfaces). The NWs were also organized into complex spatial patterns, including 1D and 2D arrays, with a controlled number of elements and dimensions. The developed TP technique enables the fabrication of bespoke nanophotonic systems using NW lasers and other NW devices as building blocks

Continuous roller transfer-printing of QVGA semiconductor micro-pixel arrays

We demonstrate an automated roll-transfer printing method for the parallel integration of >75k devices in a single shot. Automated high resolution metrology shows semiconductor micro-pixel array transfer with 1.43 μ m printing accuracy and 95 % yield

Excitation of semiconductor nanowires using individually addressable micro-LED arrays

Optical pumping of nanowire emitters, embedded in polymeric waveguides is achieved using a micro-LED array at 410 nm. The micro-LED-on-CMOS chip allows for individual pixel control and therefore parallel pumping of multiple emitters simultaneously. The nanowires are integrated on-chip using high-accuracy transfer-printing and laser lithography

Characterization, selection and micro-assembly of nanowire laser systems

Semiconductor nanowire (NW) lasers are a promising technology for the realization of coherent optical sources with ultrasmall footprint. To fully realize their potential in on-chip photonic systems, scalable methods are required for dealing with large populations of inhomogeneous devices that are typically randomly distributed on host substrates. In this work two complementary, high-throughput techniques are combined: the characterization of nanowire laser populations using automated optical microscopy, and a high-accuracy transfer-printing process with automatic device spatial registration and transfer. Here, a population of NW lasers is characterized, binned by threshold energy density, and subsequently printed in arrays onto a secondary substrate. Statistical analysis of the transferred and control devices shows that the transfer process does not incur measurable laser damage, and the threshold binning can be maintained. Analysis on the threshold and mode spectra of the device populations proves the potential for using NW lasers for integrated systems fabrication

Automated nanoscale absolute accuracy alignment system for transfer printing

The heterogeneous integration of micro- and nanoscale devices with on-chip circuits and waveguide platforms is a key enabling technology, with wide-ranging applications in areas including telecommunications, quantum information processing, and sensing. Pick and place integration with absolute positional accuracy at the nanoscale has been previously demonstrated for single proof-of-principle devices. However, to enable scaling of this technology for realization of multielement systems or high throughput manufacturing, the integration process must be compatible with automation while retaining nanoscale accuracy. In this work, an automated transfer printing process is realized by using a simple optical microscope, computer vision, and high accuracy translational stage system. Automatic alignment using a cross-correlation image processing method demonstrates absolute positional accuracy of transfer with an average offset of <40 nm (3σ < 390 nm) for serial device integration of both thin film silicon membranes and single nanowire devices. Parallel transfer of devices across a 2 × 2 mm 2 area is demonstrated with an average offset of <30 nm (3σ < 705 nm). Rotational accuracy better than 45 mrad is achieved for all device variants. Devices can be selected and placed with high accuracy on a target substrate, both from lithographically defined positions on their native substrate or from a randomly distributed population. These demonstrations pave the way for future scalable manufacturing of heterogeneously integrated chip systems

Scalable optical excitation and modulation of semiconductor nanowire emitters

We show that individually addressable micro-LED-on-CMOS arrays can be used as scalable optical excitation sources for arrayed semiconductor nanowire devices. This approach is used to demonstrate optical modulation at MHz rates of heterogeneously integrated nanowire-emitters

Transfer-printing enables multi-material assembly of integrated photonic systems

Hybrid integration of photonic membrane and nanowire devices from multiple material platforms is demonstrated using high-accuracy transfer printing. The deterministic assembly technique enables serially printed devices with separations as low as 100 nm