Life cycle assessment (LCA) of circular consumer electronics based on IC recycling and emerging PCB assembly materials.

As consumer microelectronics become ever more ubiquitous, there are growing concerns about their environmental impact. However, the diversity of designs and components used in modern devices makes a coherent mitigation strategy hard to formulate. In this work, we perform a quantitative life cycle assessment (LCA) of the environmental profiles of both high-value (a smartwatch) and low-value (a TV remote) devices and find that the optimal mitigation strategy varies substantially between these two extremes.

Exciton Diffusion to Low Energy Sites of the Acceptor Drives Charge Photogeneration in D18:Y6 Solar Cells.

We have investigated charge generation pathways in efficient organic photovoltaic blends of the polymer donor D18 and the small-molecule acceptor Y6 using transient absorption and time-resolved fluorescence spectroscopies. We find that energy transfer from D18 to Y6 outcompetes electron transfer and is followed by exciton diffusion from regions of the disordered Y6 phase to Y6 aggregates before hole transfer to D18. Aggregation of Y6 molecules increases their ionization energy by ∼0.

Nanoimprint Lithography as a Route to Nanoscale Back-Contact Perovskite Solar Cells.

Back-contact perovskite solar cells are of great interest because they could achieve higher performance than conventional designs while also eliminating the need for transparent conductors. Current research in this field has focused on making electrode structures with reduced widths to collect charges more efficiently, but current lift-off-based fabrication techniques have struggled to achieve electrode widths smaller than 1000 nm and are difficult to implement on large areas. We demonstrate nanoimprint lithography in an etch-down procedure as a simple and easily scalable method to produce honeycomb-shaped, quasi-interdigitated electrode structures with widths as small as 230 nm.

Design of cross-linked polyisobutylene matrix for efficient encapsulation of quantum dots.

Photoluminescent quantum dots (QDs) are a prominent example of nanomaterials used in practical applications, especially in light-emitting and light-converting devices. Most of the current applications of QDs require formation of thin films or their incorporation in solid matrices. The choice of an appropriate host material capable of preventing QDs from degradation and developing a process of uniform incorporation of QDs in the matrix have become essential scientific and technological challenges.

Patterning Multicolor Hybrid Perovskite Films via Top-Down Lithography.

Lead-halide perovskites have attracted great attention due to their excellent optoelectronic properties, with rapid progress being made in their performance as light-emitting diodes (LEDs), photodiodes, and solar cells. Demonstrating large scale, high-resolution patterning of perovskites is a key enabling step to unlock their full potential for a range of optoelectronic applications. However, the development of a successful top-down lithography fabrication procedure has so far been hampered by the incompatibility of perovskite films with the solvents used during lithographic processes.

Probing the structure-property-composition relationship in organic-inorganic tri-halide perovskites.

Here, we have synthesised a range of samples, with the formula (CH3NH3)1-2x(H3NC2H4NH3)xPbI3, with different levels of ethylenediammonium substitution to probe non-stoichiometry at the A-site of the perovskite. A single phase region was identified and is accompanied by a change in photophysical properties. The influence of aliovalent substitution with ethylenediammonium results in a decrease in HOMO level from -5.

Hot-Hole Cooling Controls the Initial Ultrafast Relaxation in Methylammonium Lead Iodide Perovskite.

Understanding the initial ultrafast excited state dynamics of methylammonium lead iodide (MAPI) perovskite is of vital importance to enable its fullest utilisation in optoelectronic devices and the design of improved materials. Here we have combined advanced measurements of the ultrafast photoluminescence from MAPI films up to 0.6 eV above the relaxed excited state with cutting-edge advanced non-adiabatic quantum dynamics simulations, to provide a powerful unique insight into the earliest time behaviour in MAPI.