Congratulations to Nayeun on her successful thesis defense!

Title: Nanophotonics-enhanced optoelectronics: from photovoltaics to imaging


Optoelectronics has been revolutionizing our lives through the ability to detect, generate and control light, and can be found in most of consumer electronics nowadays, such as solar cell, camera, display and laser. In these conventional optoelectronic devices, controlling the interaction between light and matter has been a key to achieve better performance. The next-generation optoelectronic devices are now required to be more compact in size due to recent advances in consumer electronics intersecting with multiple industries. Also, with advances in machine learning, implementing new functionalities are desired such as edge or object detection for autonomous vehicles, or depth sensing for augmented or virtual reality headsets (AR/VR).

Nanophotonics can be a key strategy to realize an optoelectronic device with desired functions and a smaller form factor. The field of nanophotonics aims to control the behavior of light at the nanoscale that was impossible to achieve with conventional materials and structures. It has been demonstrated that the control over local light scattering, confinement, and redirection is possible by using carefully engineered nanostructures supporting optical resonances. Using such properties, dense arrays of resonant nanostructures, often called metasurfaces, have been shown its potential to replace bulky optical components with flat optics, and even achieve new functions that are challenging to realize with conventional optics.

In this talk, I will highlight how nanophotonics can be leveraged to enhance optoelectronic devices, focusing on solar cells and imaging applications. In part 1, I will introduce methods to create light-trapping antireflection coating (LARC) using a resonant nanostructure array and implement on ultrathin solar cells. In part 2, I will demonstrate a new type of CMOS image sensor with added functionality by using engineered nanostructures.