It's a cute approach, but perovskite solar cells can probably do much better. Perovskite solar cells can be made at close to room temperature, use relatively common elements, and can be made fairly thin. The current efficiency record for perovskite solar cells is 25.6%[0].
The purpose of the article was to explore diy manufacturing of pv cells. I don't think this korean/swiss collaboration on high efficiency perovskite solar cells is within the reach of your backyard fabricator.
Perovskite cell manufacturing is quite DIYable. There's been several experiments (lab-scale, not industry-scale) with making the lead-based perovskite film from waste with very minimal equipment. The main problem is toxicity, both to people handling it and to environment if disposed of improperly. Example: https://www.youtube.com/watch?v=oQ2bz6jlbz0
Perovskites break down when exposed to moisture, so while I do think you could DIY a solar cell pretty easily, it wouldn't last long. There are ways around the moisture problem, but they're not so easily DIYable. "In particular, water promotes fast decomposition, leading to a drastic decrease in device performance." [0]
But why not more microscale concentrated solar especially for DIY? For example parabolic mirror from a thin steel plate, or just a bended steel plate, (both in themselves >90% efficient?) -> liquid salt -> steam boiler system -> DC motor seems necessarily to me be a) more efficient b) cheaper to build than perovskite and also c) the skill - level required is very low tech (except the optional liquid salt phase).
[0]https://www.pv-magazine.com/2021/04/06/unist-epfl-claim-25-6...