Yuping Shi showcases St Cross crest in paper on laser-writing patterns


A diagram of two-photon laser writing using the st cross crest

St Cross student Yuping Shi (DPhil Engineering Science, 2017) has published a paper in the journal Advanced Functional Materials

He showcases the St Cross College crest by employing the two-photon laser writing technique. Photoalignment was used to orient a liquid crystalline conjugated polymer, specifically involving two‐photon infrared laser writing of patterns in an azobenzene sulphonic dye (SD1). These patterns were transferred into the overlying film by thermotropic orientation in the nematic melt, then frozen in place by quenching to a room temperature nematic glass.


This work has pioneered high-quality alignment and ultrahigh-resolution spatial patterning of the physical structure of technologically important but otherwise structurally disordered polymeric semiconductors. By ensuring extremely high anisotropies in charge/energy transfer as well as light emission and modulation, it can enable great design flexibility and the freedom to enrich the established and emerging technologies for energy-harvesting/conversion, flexible/stretchable/molecular electronics, integrated optical circuits, and personal healthcare monitoring, and could have a huge impact on the fabrication and performance of a wide range of functional devices such as organic solar cells, LED displays, polymer lasers, thin-film transistors, thermoelectrics, spintronics, optical computing, light/gas/electrochemical sensors, and bioelectronics.

You can read the paper here.