Demonstration of a simple encapsulation technique for prototype silicon solar cells

Abstract

The impact of encapsulation on solar photovoltaic (PV) modules includes insulation and protection, which alters the device performance as a function of wavelength of incoming light. Most lab-scale PV research ignores these features, but with a promising rise in front surface spectral conversion mechanisms, methods of optical enhancement and biomimetic layers makes this oversight unacceptable. To enable encapsulation of lab-scale PV, this study evaluates a simple encapsulation method. Multi-crystalline silicon (mc-Si) wafers were encapsulated using a pouch laminator and compared with a (poly)-methyl methacrylate (PMMA) front coated cell and an unencapsulated control cell. The cell's diffuse reflectance with the encapsulant exhibits better photon absorption in the UV region, which is verified from improved external quantum efficiency. Despite the loss of a small percentage of visible photons, the electrical performances of the encapsulated cells were not affected. On the other hand, the PMMA coated cells showed an outstanding photon to electron conversion, but did not result in effective charge collection. The results show that a low-cost pouch laminate at the lab scale is an adequate method for encapsulating solar cells without overly degrading performance. In addition, for short lifetime small-scale PV applications, this method represents a means of distributed PV manufacturing.