1. Schematic diagram of perovskite quantum dot solar cells with (a) mesoporous structure and (b) planar heterojunction structure, and (c) schematic diagram of energy levels and electron transfer processes of perovskite solar cells^[23]

2. (a) Crystal structure diagram and composition regulation of PQDs (1 Å=0.1 nm); (b) Illustration of the A site cation exchange process and the corresponding photoluminescence (PL) spectra of PQDs^[26]; (c) Illustration of the electronic band structure of typical defect intolerant semiconductors and defect tolerant perovskites^[36]; (d) Schematic of Pb²⁺ at B site partially substituted by various metal ions to improve stability^[41]

3. (a) Theoretical model and adsorption energy for various ligands with different chain length adsorbed on the surface of α-CsPbI₃ QDs; (b) Schematic of the stabilization mechanism of CsPbI₃ QDs in C8 and C8/C18 ligand systems^[46]; (c) Schematic of layer-by-layer assembly of PQDs^[12]; (d) Schematic of anion and cation ligand exchange reaction of PQD films^[53]; (e) AX salt post-treatment process of the PQD films^[55]; (f) Illustration of enhanced electrical coupling between the GA-capped PQDs as a result of reduced interdot distance^[57]

4. (a) Energy band structures for SC based on PQDs with different compositions^[12] with horizontal dotted line indicating the Fermi level positions; (b) Schemati of FAPbI₃ QD/ITIC film fabrication^[60]; (c) Schematic of the charge transport process and stabilization mechanism for SC based on µ-graphene crosslinked PQDs^[64]; (d) Schematic of Cs-treatment on mesoporous TiO₂, and schematic view and J-V curve of corresponding SC with mesoporous structure^[65]; (e) P3HT modified PQD film^[71]; (f) Energy band structures of SC with different polymeric HTM^[72]

5. (a) Operating principle of a luminescent concentrator cell^[76]; (b) Photos of Yb³⁺ doped PQDs luminescent solar concentrator (LSC) under sunlight and ultraviolet radiation and its light conversion diagram^[8]; (c) Schematic illustration and energy transfer (ET) process of Mn²⁺/Yb³⁺ co-doped CsPbCl₃ quantum dots^[9]; (d) Top: near-infrared LSC using triphenylphosphine treatment strategy, below: optical efficiency of the luminescent concentrator cell coupled with LSC and silicon cell as a function of G-factor^[82]