Making exciton physics easy and affordable

We present a facile and low-cost undergraduate laboratory experiment to study exciton physics. Using a simple abrasion technique to create samples of thin-film van der Waals material samples and a low-cost spectrometer, we show that prominent excitonic features can be easily resolved in the optical transmission spectra of semiconducting transition metal dichalcogenides at ambient conditions. Our method brings interesting semiconductor quasiparticle physics to low-budget departments, hoping to expand their undergraduate laboratory curriculum.