After completing twelve years of postgraduate and postdoctoral studies, I have now begun to conduct independent scientific research. I would like to share my research experiences and reflections as I pursue my dream of scientific exploration.

Getting Started

Throughout my time in high school and college, I never envisioned a career in scientific research until December 2011, when I joined the Photonic Nose and Molecular Materials Group to pursue a graduate degree. I find great joy and focus in conducting experiments and solving problems. This passion drives me forward, pushing me to constantly seek new challenges. Despite occasional moments of doubt about my pursuit of a postgraduate degree, I am fully committed to doing my best effort in the field of research. As Zhuzi Yulei once said, “If a man wishes to accomplish something, he must first establish his will as the foundation; without this will, he cannot achieve anything.” During my doctoral program, I have dedicated myself to the experimental processes and exploration of research questions, with the goal of making a meaningful contribution to the field of supramolecular luminescent materials.

I completed my PhD under the supervision of Prof. Liu Jing, who supported me to think creatively, explore diverse literature in various fields, and encouraged me in the design and validate my experiments. This experience led me to develop and synthesize luminescent materials such as lanthanide complexes, organic fluorescent dyes, and transition metal complexes, and to study their luminescent properties and applications. Such interdisciplinary work has been beneficial to my subsequent research. Additionally, Prof. Fang Yu, the chief scientist of the group, regularly invited renowned scholars worldwide to give academic lectures and special courses during the summers, which broadened my academic horizons. Upon my graduation, Prof. Fang’s words “God rewards the diligent” resonated with me and motivated me to continue my dedication to research. I am grateful for the guidance and support throughout my scientific research journey.

When I graduated from my doctoral program, I harbored a lingering interest in conducting scientific research, leading me to engage in postdoctoral research, and this is perhaps because of that the 2016 Nobel Prize in Chemistry was awarded to three scientists in the field of “Design and Synthesis of Molecular Machines”. But when I sent countless postdoctoral cover letters to foreign scientists in the field of supramolecular research, they all came to nothing. So I asked myself, “What kind of research do you want to do in the future?” Throughout the annals of scientific history, exceptional scientists share certain traits: One is brainstorming, a propensity for generating a multitude of innovative and forward-looking ideas; another is a tendency to push scientific boundaries to the point of being textbook-worthy; the third is a rare ability to combine both of the above. While my previous knowledge encompassed lanthanide complexes, organic fluorescent dyes, and transition metal complexes of luminescent materials, I had yet to delve into the realm of quantum dots with varying sizes and distinct luminescent properties. This curiosity was fueled by a desire to understand the unique properties of quantum dots. I am grateful for the opportunity to enter the field of quantum dots research during my postdoctoral period, and the 2023 Nobel Prize in Chemistry was bestowed upon three scientists for their contributions to the discovery and synthesis of quantum dots.

Carrying On

During my postdoctoral interview with Prof. Peng Xiaogang’s group in the Department of Chemistry at Zhejiang University, Assoc. Prof. Qin Haiyan asked me “Why did you choose Prof. Peng’s group?”, and I replied “I am more interested in quantum dots”. She continued to ask that “There are so many groups working on quantum dots, why don’t you go to other groups?”, and I answered, “I only know Prof. Peng in the field of quantum dots”. It seems to be a bit complimentary to many people, but in the field of quantum dots, I only knew Prof. Peng at that time. Despite I didn’t aware of Prof. Peng’s significant reputation in the field of quantum dots, I know that his approach to excellence in scientific research and brainstorming inspires.

After joining Prof. Peng’s group, I was initially engaged in quantum dot spectroscopy, which was completely unrelated to the research I had done during my master’s and doctoral programs, and I had to learn the basics of semiconductor physics, spectroscopy, and the construction of optical circuits. The first two years of my postdoctoral career were extremely difficult, and I sometimes felt suffocated. I happened to read the wise words of Marshal Ye Jianying, “A fortress is not to be feared, a book is not to be feared. Science has its dangers and obstacles, but hard work can get us through.” It made me regain the confidence to carry on. In the third year after my PhD program, I discovered the surface defect states of semiconductor nanocrystals dependent on the crystal surface, and the corresponding results were published. Meanwhile, Prof. Peng suggested that my experimental skills were more suited to synthetic chemistry. Due to my background in chemistry, I replied to Prof. Peng, “I have a poor foundation in photophysics, so I chose spectroscopy as my first research topic, and then based on the knowledge of spectroscopy, I would like to do some oriented synthetic chemistry of quantum dots, which is different from purely doing synthetic chemistry.” Prof. Peng agreed with my opinion. At the same time, he suggested that I should continue to broaden my knowledge and read more literature in interdisciplinary fields, and eventually develop my own research characteristics. In the same year, I returned to the Photonic Nose Group, and Prof. Fang also suggested that I should combine synthetic chemistry and spectroscopy to do some special research works. The coincidental suggestions of the two teachers made me start to think about the characteristics of my future research.

Growing and Advancing

After three years of postdoctoral research, I made the decision to delve deeper into the new topics discovered in Prof. Peng’s research group. Through a serendipitous experiment, I successfully tackled a forty-year longstanding challenge in the field of quantum dots synthesis --- “Synthesis of artificial molecules of colloidal quantum dots”. This breakthrough brought great excitement to both Prof. Peng and myself. Despite initial difficulties in reproducing the results or achieving high yields over the course of a year, persistent efforts and reflections eventually led to the successful preparation of various monodispersed artificial molecules showcasing quantum states characteristics. This has reinforced my commitment to further exploring this research area, using unique spectroscopic properties as a guide and synthetic chemistry as a foundation for developing semiconductor nanocrystal materials with specialized properties. This may become a prominent focus of my future research endeavors.

During my postdoctoral research at Zhejiang University, I had the privilege of interacting with exceptional teachers and fellow students, just as the symbiotic effect of “Being with good people makes you better too”. This experience provided valuable insights into the mindset, learning strategies, and experimental design techniques prevalent in top scientific laboratories. Although the postdoctoral research journey was challenging and filled with obstacles, it also opened doors to uncharted fields, fueling my desire to innovate and develop novel substances that can benefit humanity in my scientific research.

I have been fortunate to have met mentors in the process of searching for my dreams in scientific research, who have guided me in the direction of my own advancement. As I now transition into a teaching role, I am compelled to contemplate how I can serve as a guide for students on their research journeys and how I can conduct meaningful and impactful scientific investigations.

About the Author: Lei Hairui is a senior researcher and a doctoral supervisor at Inner Mongolia University.He received his PhD degree in Science from Shaanxi Normal University in 2017 under the supervision of Prof. Liu Jing. He was a postdoctoral researcher at the Department of Chemistry of Zhejiang University from 2017-2023 under the supervision of Prof. Peng Xiaogang. He joined the College of Energy Material and Chemistry of Inner Mongolia University in 2023. In recent years, he is mainly engaged in the precise synthesis and surface chemistry of colloidal semiconductor nanocrystals and single-molecule spectroscopy. He has published 18 papers in Acc. Chem. Res., J. Am. Chem. Soc. and ACS Nano, and has been authorized 4 Chinese invention patents.