Research

Perovskite Electronics

  • Perovskite Light-Emitting Diodes (PeLEDs)

Organic/inorganic hybrid perovskite has much higher color-purity and lower cost compared with organic emitters and inorganic QD emitters. Also efficiency of PeLED can be increased by fine stoichiometric tuning that prevents exciton dissociation, and nanograin engineering that reduces perovskite grain size, and concomitantly decreases exciton diffusion length.

Our study reduces the technical gap between PeLEDs and OLEDs or quantum dot LEDs and is a step toward the development of efficient next-generation emitters with high color purity and low fabrication cost based on perovskites.

[References]

1. Science (2015), 350, 1222 

2. Advanced Materials (2015), 27, 7, 1248 

3. Advanced Materials (2016), 28, 7515

4. Proc. Natl. Acad. Sci. U S A (2016), 113, 11694

5. Advanced Materials (2017), DOI:10.1002/adma.201700579

  • Synthesis of perovskite nanocrystal (NCs) and perovskite quantum dots(QDs) for PeLEDs

We chemically synthesize metal-halide perovskite nanocrystals (NCs) beyond quantum size effect (diameter > exciton Bohr diameter) and perovskite quantum dots (QDs) under quantum size effect (diameter < exciton Bohr diameter) by using re-precipitation methods and hot-injection methods. We can also control their dimension, opto-electronics properties and shape by ligand-engineering process. These perovskite emitters showed high luminescence efficiency due to efficient exciton confinements and surface-defect passivation by organic ligands. With these methods, high efficiency PeLEDs based on perovskite NCs and QDs can be fabricated

[References]

1. ACS Nano (2017), 12, 6586–6593

2. Nano Energy (2017), 38, 51

  • Perovskite Solar Cells

 The organic-inorganic hybrid perovskite solar cell, which is cheap and easy-to-make photo-absorption materials, has highly increased the power conversion efficiency of thin film solar cells in the recent years. We also used the work function controllable conducting polymers as the efficient charge extraction interlayer in perovskite solar cells.

[References]

1. Energy & Environmental Science  (2016), 9, 12

2. Energy & Environmental Science (2016), 9, 932

3. Advanced Materials (2014), 26, 37, 6461

4. Advanced Materials Interfaces (2016), 3, 1500678