Researchers from South Korea’s Electronics and Telecommunications Research Institute (ETRI) have reported the development of technology to mass-produce quantum dot lasers using metal-organic chemical vapor deposition (MOCVD) systems. The work paves the way to reducing production cost of semiconductor lasers to a sixth of the current cost. The researchers demonstrated the technology by developing indium arsenide/gallium arsenide (InAs/GaAs) quantum dot laser diodes on gallium arsenic (GaAs) substrates, which are suitable for the 1.3 µm wavelength band used in optical communications. “The mass production technology for quantum dots can significantly lower the production costs of high-priced optical communication devices, enhancing the competitiveness of the national optical communication component industry and contributing substantially to basic science research,” said professor Dae Myung Geum of Chungbuk National University and a participant in the research. A process developed by researchers at South Korea’s Electronics and Telecommunications Research Institute (ETRI) uses metal-organic chemical vapor deposition systems (shown) to manufacture quantum dot lasers at a lower cost and with better results compared to molecular beam epitaxy. Courtesy of ETRI. Traditionally, quantum dot laser diodes have been produced using molecular beam epitaxy. This method suffers inefficiencies due to slow growth speed, which poses challenges for mass production. MOCVD, on the other hand, has higher production efficiency which presents an opportunity to significantly enhance the productivity of quantum dot laser manufacturing. Quantum dot lasers are known for their excellent temperature characteristics and strong tolerance to substrate defects, allowing for larger substrate areas and consequently lower power consumption and production costs. The method developed by the researchers provides high density and good uniformity, the researchers said. The produced quantum dot semiconductor lasers demonstrated continuous operation at temperatures up to 75 ºC, which, according to the researchers, represents a world-leading result in yield quality obtained via MOCVD. Previously, optical telecommunication devices used expensive 2-inch indium phosphide (InP) substrates, resulting in high manufacturing costs. The new technology, using GaAs substrates, which are less than one-third the cost of InP substrates, is projected to reduce the manufacturing cost of communication semiconductor lasers to less than one-sixth. “This research outcome is a prime example of securing both commercial viability and fundamental innovation, potentially changing the paradigm of the semiconductor laser industry for optical communications,” said Ho Sung Kim of ETRI's Optical Communication Components Research Section. The research team plans to further optimize and verify this technology to enhance its reliability and transfer it to domestic optical communication companies. These companies will receive key technology and infrastructure support through ETRI's semiconductor foundry, accelerating the commercialization timeline. The anticipated reduction in development time and production costs is expected to enhance product price competitiveness, potentially increasing market share internationally. The research was published in the Journal of Alloys and Compounds (www.doi.org/10.1016/j.jallcom.2024.173823).
