{"id":10745,"date":"2020-12-17T11:49:26","date_gmt":"2020-12-17T17:49:26","guid":{"rendered":"https:\/\/www.thermofisher.com\/blog\/materials\/?p=10745"},"modified":"2026-02-03T16:36:09","modified_gmt":"2026-02-03T22:36:09","slug":"improving-solar-cell-efficiency","status":"publish","type":"post","link":"https:\/\/www.thermofisher.com\/blog\/materials\/improving-solar-cell-efficiency\/","title":{"rendered":"Solar Cell Efficiency"},"content":{"rendered":"

History of solar cells<\/h2>\n

Working with metal electrodes in an electrolyte solution, French physicist Alexandre-Edmond Becquerel discovered the photovoltaic effect when he noticed that small electric currents were produced when silver chloride or silver bromide coated electrodes in an electrolyte solution were exposed to light. Over the next century, scientists continued to experiment with electrochemical materials that respond to light, leading to the development of the solar cell that today promises to help eliminate human dependence on energy from fossil fuels.<\/p>\n

High efficiency solar cells<\/strong><\/h2>\n

To create better solar cells, it\u2019s important to understand the electrical properties of their materials. A fundamental property of elements is band gap (or energy gap), which is the minimum energy required by the electrons in the outermost shell of an atom to jump free of the atom, leaving a \u201chole\u201d in the material. Materials such as copper have minimal band gap values, making them good conductors. Insulator materials have very high band gaps. And in the middle are semiconductors with intermediate band gap energies, measured in electron volts where one electron volt is the amount of kinetic energy gained by a single electron accelerating from rest. For example, silicon has a band gap of 1.1 electron volts.<\/p>\n

While widely in use for decades, silicon-based solar cells have several disadvantages. Compared to newer technologies, solar grade crystalline silicon is heavy and inflexible. Several newer forms of silicon have been developed, but none of these materials can improve on the band gap properties of silicon.<\/p>\n

Thin film solar cells<\/strong><\/h2>\n

The second generation of solar cells are thin-film cells made up of very thin layers of photon-absorbing material layers deposited over a flexible substrate. The layers range in thickness from a few nanometers to tens of nanometers and use materials with high band gap values. The cells may be composed of metallic contacts such as zinc oxide and molybdenum surrounding a softer material, for example, copper-indium-gallium-selenide film (CIGS) and cadmium-sulfur (CdS). And they require thin-film technologies that are able to separate and analyze the various layers of these constructions.<\/p>\n

\"Illustration

Researchers are increasingly turning to XRD, XPS, and UPS as they strive to improve the efficiency of second-generation thin-film solar cells.<\/p><\/div>\n

Today, scientists are increasingly turning to three techniques as they work to improve the efficiency of thin-film solar cells:<\/p>\n