In the 21st century, the world faces more serious problems on energy, environment, food, and disease than ever before. To come up with these fundamental issues, light could be one of the ideal solutions as it is one of nature’s mechanism carrying energy and information from one place to another by wavelength and frequency. Understanding how light is absorbed and transformed into more useful forms of energy would give insight into how photosensitizers can be designed to harness and control light more effectively. Along with that, we have researched on organic photosensitizers for the following applications: (i) energy harvesting (dye-sensitized solar cells, polymer solar cells, and perovskite solar cells) and (ii) storage (supercapacitors and batteries) systems for green environment, and (iii) bioapplications (organelle probe and photodynamic therapy) to overcome chronical diseases (cancer and Alzheimer’s). In addition, we develop (iv) ultrasonic spray chemistry for hetero/multi-atom doped carbon-based materials and conjugated microporous polymer materials, followed by their applications into energy storage and/or catalysts (CO2 reduction and N2 fixation). Thus, our research will contribute on sustainable goals adopted by UN, such as food (F), energy (E), environment (E), and disease (D), to achieve a better and more supportable future for all of us.