Fig. 1. Schematic diagram of structure of the FDTD optical simulation model

Fig. 2. Effect of individual parameter change on T, P and K

Fig. 3. Effect of diamond nanopillar height and diameter combination optimization on T, P and K

Fig. 4. Effect of DLC film upper and lower diameter combination optimization on T, P and K

Fig. 5. Effect of different DLC film thickness on T, P and K

Fig. 6. Influence of the position shift of the nanopillar light source on T (a), P (b) and K (c) values with or without DLC filmand the corresponding differences (d)

Fig. 7. (a) Overall electric field distribution of nanopillar with DLC film; (b) Overall electric field distribution of nanopillar without DLC film; (c) Difference of electric field intensity on central axis