Imagine walking into a room and switching on the wallpaper, which promptly lights up the space. In the near future, we could be ditching light bulbs in preference of a new type of energy-efficient technology that could make illuminated wallpaper a reality, according to Shuai Zhigang, a chemistry professor in Tsinghua University.

His wallpaper idea is based on theoretical chemistry research, which explains or predicts chemical phenomena using physics. In particular, Shuai researches electronic structure, dynamics and their application.

The light-emitting wallpaper that Shuai mentioned uses organic light-emitting diode (OLED), which is produced by "printing" a film of organic electro-luminescent compounds onto a flat carrier. The carrier can be a polymer substance such as wallpaper.

If OLED is widely used in illumination, it will save enormous amount of electricity and money. A survey conducted by China Green Lights Promotion Project Office showed that China consumes 300 billion kwh of electricity for lighting each year. If the country replaced all the light bulbs or some of the fluorescent lights used now, it would lead to a saving of up to a third of the electricity used for illumination. The 100 billion kwh saved would be equivalent to the annual electricity generated by the Three Gorges' Project, a project that cost 200 billion yuan ($29.28 billion).

The U.S. Department of Energy has also conducted a similar study. It projected that if half of the light bulbs in the United States were replaced by OLED, it would save $35 billion in electricity costs.

OLED has a broad future, according to Shuai, who is one of the leading Chinese scientists in OLED technology. As a theoretical chemist, his job is to predict the property of materials by studying their molecular structure. In 2002, he was invited by the China Academy of Sciences to participate in Project 973, a scientific research project.

With funding from the project, Shuai worked with Belgian scientists Jean-Luc Brédas and David Beljonne to make significant progress in OLED technology. Their theoretical research showed that the luminous efficiency of OLED could go far beyond the 25 percent limit predicted by the spin-statistics theorem in quantum mechanics.

Previously, some scientists predicted that the luminous efficiency of OLED could not go beyond 25 percent, although this was hotly debated and empirical evidence was unclear.

While it might take some time for OLED to supplant light bulbs in home illumination, OLED has huge potential in the display panel market. In fact, OLED has already been used in screens for small electric appliances such as digital cameras and cell phones. Several years ago, industry analysts predicted that the global OLED display panel market in 2009 would reach $3.1 billion and the technology has attracted the attention of investors worldwide.

Compared with the non-organic light-emitting diode (LED), OLED has several advantages. It is relatively easier to produce and can be made into a thin soft layer. Also, OLED does not have strict requirements for the carrier panel, so it can be "smeared" onto soft plastics, glass or metal sheets.