Display panel, preparation method thereof and display apparatus

A display panel, comprising a substrate, a first electrode, at least two emission functional layers and a second electrode, wherein

• the first electrode, the at least two emission functional layers, and the second electrode are sequentially stacked on a side of the substrate;
• for any two adjacent ones of the at least two emission functional layers, one of the emission functional layers close to the substrate comprises a first hole transport layer, a first emission layer, a first electron transport layer, and an N-type charge generation layer, and the other of the emission functional layers away from the substrate comprises a P-type charge generation layer, a second hole transport layer, a second emission layer, and a second electron transport layer;
• the first hole transport layer, the first emission layer, the first electron transport layer, the N-type charge generation layer, the P-type charge generation layer, the second hole transport layer, the second emission layer and the second electron transport layer are sequentially stacked away from the substrate;
• the first electron transport layer has a thickness ranging from 3 nm to 10 nm;
• the first emission layer comprises a first pattern, a second pattern, and a third pattern, wherein
• the first pattern, the second pattern, and the third pattern have orthographic projections on the substrate spaced apart from each other and emit light of different colors;
• the first electron transport layer comprises a first subportion, a second subportion and a third subportion which have orthographic projections on the substrate spaced apart from each other, wherein
• orthographic projections of the first subportion and the first pattern on the substrate are overlapped,
• orthographic projections of the second subportion and the second pattern on the substrate are overlapped, and
• orthographic projections of the third subportion and the third pattern on the substrate are overlapped;
• and
• the first subportion has a thickness smaller than a thickness of the second subportion, and
• the first subportion has a thickness smaller than a thickness of the third subportion.