Crystalline silicon solar panels fall under two categories: monocrystalline and polycrystalline solar cells. Both rely on very thin layers of silicon in solar panels (as well as other rare materials) to absorb sunlight. Typically, people use thin film solar panels less commonly than silicon solar panels, but we should consider them nonetheless! They require far less silicon during the manufacturing process and are gradually becoming more popular. When debating between thin film and crystalline solar panels, remember that thin film panels typically contain cadmium — a carcinogenic substance. However, cadmium mainly emits. As solar technology continues to advance, thin film solar panels have the potential to surpass crystalline panels in popularity. Although crystalline silicon.