Shaping Organic Microcrystals Using Focused Ion Beam Milling

The technique of focused ion beam (FIB) milling is used to cut two-dimensional shapes into single crystals composed of the organic semiconductor molecule perylene. The use of an ultrathin Au coating and its removal using a KI/I-2 etchant solution allow the crystal to be imaged in the FIB apparatus while protecting it from electron beam damage. Using this approach, features with a spatial resolution on the order of 130 nm can be created while retaining 90% of the original photoluminescence intensity in the surrounding crystal regions. These proof-of-principle experiments demonstrate that FIB milling could provide a general way to control the nanoscale morphology of organic molecular crystals.