The Review 2008

32 33 Efficient organic solar cells not only need to absorb sunlight, they must separate positive and negative charges and collect electrons. The device produced at HKU, in collaboration with colleagues from Baptist University, performed well on both counts and was par ticularly good at absorbing sunlight at longer wavelengths.The results were published in Nature Materials in 2007. Professor Chan and Dr Djurisic said organic solar cells were not yet commercially viable, unlike silicon cells which are considerably more complicated and expensive to produce but achieve higher efficiency. But they believed they would eventually become so through the development of new materials. Basic research is the key and even it if takes time to find the right material, the results, both positive and negative, will still have scientific value. “We are learning more about how these devices work so we can make better devices,” Dr Djurisic said. “In any case, if you learn new concepts related to cell performance, you can apply what you learn to other things, even if your par ticular material is not optimal. It’s still of scientific interest even if it doesn’t give an immediate answer to the energy crisis.” Dr Aleksandra Djurisic and Professor W.K. Chan Major Study on Treating Psychosis Psychosis is a frightening disease for patients and their families. It can bring on delusions and hallucinations and disturb speech and thought patterns. Early intervention and focused treatment are essential, but this poses challenges for health providers. A new $68.2 million project at the University hopes to find some solutions. In Hong Kong the prognosis of patients can be harmed by the stigma attached to psychotic disorders, which are caused by brain diseases that affect behaviour and cognition, and by the lack of awareness among the public and frontline medical officers. Both factors can delay intervention. Moreover, emerging research has shown that even when there is proper treatment and management, current regimes may not be sufficient. Patients received a standard two years of follow up, but this may need to be extended to three to five years to effectively improve their outcome. The new project, which is being overseen by Professor Eric Chen of the Depar tment of Psychiatry and funded by The Hong Kong Jockey Club Charities Trust, will test that theory and seek to improve treatment for psychosis patients. Currently patients aged 25 or over are placed in general adult psychiatric clinics, which are crowded and offer brief consultation times and relatively infrequent follow up. Younger patients receive targeted treatment and support but this only lasts for two years. The five-year project will provide intervention and suppor t services for 1,000 psychosis patients over 25, and under take random clinical trials on two-year and four-year treatment regimes.The results are expected to have international significance for treating psychosis. The project will also assess the cost-effectiveness of treatment, train gatekeepers in detecting psychosis in the early stages, and carry out public education to help remove the stigma from the disease. Shining Light on Solar Cells Concern about climate change is fuelling the quest for a better solar cell, a device that conver ts the sun’s rays into energy. Scientists at HKU have joined the quest, creating a metal organic polymer cell that can be cheaply produced and, so far, achieves an efficiency rate of four to five per cent, comparable to the best results in the world for organic solar cells. “An organic solar cell device is very simple in theory: the key is the active material absorbing sunlight. A 10 year old can make a simple one with raspberry juice,” said Dr Aleksandra Djurisic of the Depar tment of Physics, who collaborated on the research with Chemistry Professor W.K. Chan. “But if you are after high efficiency then things get more complicated. This requires multi-disciplinary research.” The Review 2008 • Research