Light Adv. Manuf. | Laser Direct Writing Assists Perovskite Optoelectronic Applications

Introduction
Metal halide perovskites have excellent optoelectronic properties and have become the undisputed "star" materials in the semiconductor field, attracting great attention from both academia and industry. With a large amount of research investment, the application of perovskite covers various optical and optoelectronic fields such as single photon sources, micro nano lasers, photodetectors, optical logic gates, optical communication, waveguides, nonlinear optics, etc. Therefore, building and integrating photonic devices with different functions based on a single perovskite chip is very promising.

The development of micro nano processing technology is a crucial step in integrating various optoelectronic devices onto a single chip to meet the requirements of advanced integrated optics, and will play a crucial role in the development of next-generation information technology.
Laser direct writing (DLW) is an efficient, non-contact, maskless micro/nano processing technology that couples the laser beam with a microscope to reduce the size of the output spot and achieve high-resolution micro/nano processing. According to the manufacturing mechanism and material threshold response, the optimal resolution of DLW is usually between a few to hundreds of nanometers. Meanwhile, DLW can flexibly manufacture any micro/nanostructure on the same substrate, and can also use spatial light modulators to change the focused laser field into a specific shape or generate multiple focal points simultaneously, thus meeting the needs of large-scale manufacturing.

Recently, Associate Professor Gan Zhixing from Nanjing Normal University, in collaboration with Professor Jia Baohua and Researcher Wen Xiaoming from Royal Melbourne Institute of Technology, published a review paper on "Direct laser writing on halide perovskites: from mechanisms to applications" in Light: Advanced Manufacturing. The paper reviewed the latest progress of DLW in the field of perovskite semiconductors, revealed the interaction mechanism between light and perovskite during laser direct writing, and introduced the application of DLW processed micro nano structured perovskite in optoelectronic devices. Finally, the future prospects and challenges of this technology were summarized.

Figure 1: Mechanism and application of interaction between laser and perovskite

The interaction mechanism between laser and perovskite
Laser has unique advantages such as high precision, non-contact, easy operation, and no mask, making it an excellent tool for operating, manufacturing, and processing micro and nanostructures on semiconductors. The specific interaction mechanism between laser and perovskite can be divided into various phenomena such as laser ablation, laser induced crystallization, laser induced ion migration, laser induced phase separation, laser induced photoreaction, and other laser induced transformations. These different mechanisms of action represent different changes in perovskite crystals. For example, laser induced crystallization is the nucleation and crystallization process of perovskite precursors, while laser induced phase separation is the process of separating mixed perovskite phases into two different phases, both of which contain rich physical phenomena. The implementation of the entire micro nano machining process is influenced by DLW parameters, such as wavelength, pulse/continuous wave, action time, power, and repetition frequency. The selection of these parameters provides a flexible and powerful tool for precise control of the microstructure of perovskite.

Optoelectronic applications of micro nano structured perovskites manufactured by DLW
The perovskite material processed by DLW has a wide range of applications in fields such as solar cells, light-emitting diodes, photodetectors, lasers, and planar lenses, exhibiting superior performance. At the same time, due to the unique ionic properties of perovskites, they exhibit phenomena such as ion migration, phase separation, and photochromism under continuous laser action, thereby expanding their applications in multi-color displays, optical information encryption, and storage.

Challenges and Prospects
Compared with traditional semiconductor manufacturing techniques, DLW technology greatly improves manufacturing efficiency due to its simple operation process and high-throughput characteristics, and is expected to produce high-resolution complex micro/nanostructures on a large scale. The combination of cheaper and more flexible controllable lasers with the superior optoelectronic performance of perovskite semiconductors will bring enormous potential for the preparation of micro nano structured perovskite optoelectronic devices. At present, relevant research is still in its early stages and some key technical bottlenecks need to be addressed. It is expected that in the near future, when these bottlenecks are overcome, significant progress will be made in related basic research and industry.

Source: Sohu