Shaurjo Biswas

Solvent-free, direct printing of organic semiconductors in atmosphere

Additive, solvent-free printing of molecular organic semiconductors in ambient atmosphere is demonstrated, by evaporating organic source material into nitrogen carrier gas, collimating and impinging it onto a substrate where the organic molecules condense. A surrounding annular guard flow focuses the primary jet and shields it from contact with the ambient oxygen and moisture, enabling device-quality deposits. As an example, electroluminescence efficiency of organic light emitting devices (OLEDS) with emissive layers printed in air is shown to increase with guard flow rate, attaining parity with all-vacuum thermally evaporated OLEDs.

Minimal architecture zinc–bromine battery for low cost electrochemical energy storage

We demonstrate a minimal-architecture zinc–bromine battery that eliminates the expensive components in traditional systems. The result is a single-chamber, membrane-free design that operates stably with >90% coulombic and >60% energy efficiencies for over 1000 cycles. It can achieve nearly 9 W h L−1 with a cost of <

Growth and modelling of spherical crystalline morphologies of molecular materials

100 per kWh at-scale.

Corrigendum: Growth and modelling of spherical crystalline morphologies of molecular materials

Crystalline, yet smooth, sphere-like morphologies of small molecular compounds are desirable in a wide range of applications but are very challenging to obtain using common growth techniques, where either amorphous films or faceted crystallites are the norm. Here we show solvent-free, guard flow-assisted organic vapour jet printing of non-faceted, crystalline microspheroids of archetypal small molecular materials used in organic electronic applications. We demonstrate how process parameters control the size distribution of the spheroids and propose an analytical model and a phase diagram predicting the surface morphology evolution of different molecules based on processing conditions, coupled with the thermophysical and mechanical properties of the molecules. This experimental approach opens a path for exciting applications of small molecular organic compounds in optical coatings, textured surfaces with controlled wettability, pharmaceutical and food substance printing and others, where thick organic films and particles with high surface area are needed.

Improving the cycle life of a high-rate, high-potential aqueous dual-ion battery using hyper-dendritic zinc and copper hexacyanoferrate

Corrigendum: Growth and modelling of spherical crystalline morphologies of molecular materials