Do you know how thin-film modules are manufactured?
You probably know how silicon-based modules are manufactured (typically with monocrystalline half-cells). The process for thin-film modules, however, is very different.
It consists of four layer additions or depositions and four laser cuts:
1️⃣ Transparent conductive oxide (TCO)
2️⃣ Absorber layer deposition (CdSeTe)
3️⃣ Back contact deposition (ZnTe)
⚡ Laser cut through 1+2+3 for cell isolation
⚡ Laser cut through 2+3 for cell interconnect
4️⃣ Rear conductor deposition
⚡ Laser cut through 4 for rear cell isolation
⚡ Laser cut through 1+2+3+4 for grid application
This results in a configuration with much higher number of cells in series (200+) and much higher number of series in parallel than in a typical silicon based module.
For this reason, a thin film module operates at much higher voltage (can be higher than 200 V) and lower current (can be lower than 3 A).
They also behave pretty well with partial shading, especially with uniform row-to-row shading, which is the most common use case for this type of module. This is the reason why they normally do not have any bypass diodes.
If you want to learn more about the entire process, the hardware manufacturer First Solar has created this great 3D animation showing all the details. 😍