Solar Panels are developed with increasingly advanced and energy-efficient materials, and advances in production techniques and materials science have lowered costs of solar panel production over the last few decades. At present, the current leader in commercial efficiency is SunPower, who produce a solar panel with an energy conversion ratio of over 19.3%.
Encapsulate - This outer layer protects the solar panel from the environment, and prevents corrosion - which in turn can decrease efficiency.
Contact Grid - This conductive grid collects electrons in the solar cell.
Anti-Reflective Coating - this coating allows the solar panel to absorb more photons, and thus improves the solar panel's conversion ratio.
P and N type Semicoductors - These layers use the energy of photons striking the panel to free electrons and electron holes into an electric field, which drives current into an external load.
For rigid solar panels, the solar cells and the panel module are produced at the same time. The solar cells are directly implanted on the solar panel's glass substrate, and the electrical connections are wired directly on creation of the cells. For flexible solar panels, the constituent solar cells are laminated unto a clear fluoropolymer on the top of the panel.
A solar panel is typically constructed to absorb wavelengths from a portion of the solar spectrum, but typically certain wavelengths are not captured due to the nature of the solar panel's construction, particularly ultraviolet or infrared light. The broader the absorption spectrum, the more potential efficiency a solar panel can achieve.