The TCS-PES was until now only applied to hybrid perovskite solar cells. We wanted to extend the scope of the TCS-PES to III-V semiconductor devices. In contrast to soft materials like organic-inorganic perovskites, organic hole extraction layers, and gold contacts that compose perovskite solar cells, III-V materials are much stiffer and brittle. For that reason, we used a mechanical polishing machine where the force applied to the sample can be adjusted (see Figure ). The machine also allows applying radial and axial angles to create the targeted tapered cross-section. An increment of 0.02° can be used for the adjustment of the angle. The MULTIPREP TM polishing system seems to provide a more controlled way to prepare the TCS than manual polishing techniques although more TCS samples would be required to confirm such a statement. It should also be mentioned that glueing the sample on the sample holder is a critical step because it can induce unintentional angles. It explains why some of the TCSs were obtained without applying any angle (see Table -Supplementary Information (SI)).