The inventor of a room-temperature nanowire laser and the co-inventors of the OLED have both been tipped to win Nobel Prizes, according to analysis of scientific literature citations by Thomson Reuters.
Thomson Reuters makes its Citation Laureates study each year and has successfully predicted 35 Nobel Prize winners since 2002. The study is based on analysis of data within the Web of Science; it identifies the most influential researchers, and therefore those likely to win the Nobel Prize, in the categories of chemistry, physics, physiology or medicine, and economics.
Among the predictions, Piedong Yang, a professor at the University of California, Berkley, is one of the researchers tipped to win the Nobel Prize in Physics for his contributions to nanowire photonics, while Dr Ching Tang and Steven Van Slyke have been predicted to win the Nobel Prize in Chemistry for their work on organic light emitting diodes (OLEDs).
The Nobel Prize winners are due to be announced between 6-13 October, and will be honoured at the Nobel Prize Award Ceremonies in Stockholm, Sweden on 10 December.
Yang's research group studies the synthesis and application of nanomaterials, and while the group focuses on the application of nanowires in many different fields, including pholtovoltaics, artificial photosynthesis, and thermoelectrics, Yang is tipped for the Nobel Prize particularly for his contributions to nanowire photonics.
Nanowires exhibit electrical and optical properties that bulk materials do not because of their high length-to-width ratio - they have a diameter of around a nanometre but are 1,000 times longer. This geometry causes quantum confinement, which results from the electrons being squeezed into a dimension approaching an important physical constant, the exciton Bohr radius. This quantum confinement phenomenon is responsible for other effects; for instance, the electrical conductance of the nanowires is quantised.
The nanostructures are therefore ideal for the development of integrated photonics devices for computing, communications and sensing, as a fundamental factor in this is being able to manipulate optical energy in structures smaller than the wavelength of light.
Yang has achieved several research milestones in this field, one of the most notable being the development of the first room-temperature nanowire laser in 2001. Yang and his research team first synthesised zinc oxide nanowires, and then produced light by optically pumping the nanowires − raising the electron’s energy levels − using light from a visible laser. This invention has been used widely as a miniature light source in computer chips.
Yang's research group is currently assessing the potential for nanoscale photonic elements, with the aim of constructing nanowire photonic circuitry.
Thomson Reuters' Citation Laureates study also predicted that Van Slyke, CTO of OLED printing company Kateeva, and Dr Ching Tang, professor of chemical engineering at the University of Rochester, as potential winners of the Nobel Prize in Chemistry for the joint invention of the organic light emitting diode (OLED). Their seminal paper on the topic was published in the journal Applied Physics Letters in 1987. Since then, it has been cited in more than 5,000 publications.
Van Slyke and Dr Tang were working together at Kodak when they invented the OLED, a technology that is now ubiquitous in smartphones, tablets and high definition televisions. OLEDs are flexible, thin, ultra-light, and more energy-efficient than LCDs.
The invention was made after Dr Tang discovered that when a light voltage is applied to organic thin-film photovoltaics, light is emitted. Van Slyke then found the suitable organic compounds needed to sustain the emitted light. One of these organic materials was metal chelate, an organometallic compound, which the pair then incorporated into an OLED device and left overnight. In the morning, they found that it was still glowing, and with the same level of brightness.
The metal chelate compound was refined by the pair over the following decade, until they could finally demonstrate OLED devices that emitted red, blue and green colours, as well as a suitable manufacturing process. The OLEDs were self-illuminating, and were capable of converting electrical energy into light, through the use of a stack of thin organic layers sandwiched between a transparent anode and a metallic diode.
Although the invention was made in the late 80s, the first commercial product wasn’t released until 2003; this was a Kodak camera equipped with a 2.2-inch OLED screen. Other companies followed, and it is now present in numerous commercial technologies today. According to market reports, the OLED industry will represent a global market of almost $170 million by 2020.