Technology

Crystalline silicon photovoltaic (PV) technology was first developed more than 50 years ago based on silicon wafers, and is known as 1st generation solar technology. Silicon-based technology is technically proven and reliable, and has succeeded in achieving market penetration, primarily in off-grid remote areas and in grid-connected applications where sufficient subsidies are available to offset its high cost.

There are several inherent limitations to this 1st generation like Silicon wafers are fragile, making processing difficult and limiting potential applications. The process is very labor and energy intensive and manufacturing plant capital costs are high, limiting scale-up potential. And because materials represent more than 50% of manufacturing costs and silicon supply is finite, the long term potential for cost reduction is insufficient to deliver broadly affordable energy.

To simplify manufacturing and reduce costs, a 2nd generation known as thin film technologies was developed. These technologies are typically made by depositing a thin layer of photo-active material onto glass or a flexible substrate, including metal foils, and they commonly use amorphous silicon (a-Si), copper indium gallium diselenide (CIGS), or cadmium telluride (CdTe) as the semiconductor. Thin film PV is less subject to breakage when manufactured on a flexible foil. However, efficiency remains lower than that of 1st generation solar.

OPV are third generation PV cells which use an organic polymer layer to convert light into electricity. In a typical OPV, a polymer composite layer is sandwiched between two metal contacts, one of which must be transparent. Additionally, interfacial layers are used to facilitate the electricity flow between the polymer layer and the contacts. The polymer layer is typically consisted of a polymer donor and an acceptor. The layer absorbs light (or photons), converts into electrons and holes, which are transported to the contacts to generate electricity.

OPV cells printed on a flexible substrate are consist of non-toxic materials and are cost competitive as they can be easily manufactured by roll-to-roll processes. In addition, OPV have better performance in low light, can be transparent and colorful, and have greater flexibility and lower weight. OPV is the first PV technology capable of generating electricity at a cost on par with conventional fuels, making it a cost-effective renewable energy source without government subsidies.

Advantages

§   Low cost and Low temperature process

§    Light weight

§    Flexible, Biodegradable

§    Semi-transparent

§    Complementary spectrum coverage