A large area (6,270 mm2) D5A-based device prepared with the slot die-coating method was found to exhibit a best PCE of 6.54%, which is significantly better than that of the equivalent D1A-based large area device (4.03%).
The reflectance peak of the modified device prepared with 5~10 nm TiO2 nanoparticles is different from that prepared with 40 and 100 nm TiO2 nanoparticles, with peak positions at 700, 750, and 750 nm, respectively (Fig. 1d f).
The device prepared with composite electrodes containing 20 wt% of carbon black exhibited a capacity of 0.7 F cm−3 under 2 V providing an energy density of 0.4 W h l−1.
The modified devices prepared with 2000 and 1000 μm/s show the optical contrasts of 49 and 50%, respectively, which is slightly higher than that of the modified device prepared with 3000 μm/s (48%).
Basically, the maximum transmittance of 70% is achieved for modified device prepared with precursor concentration of 1 4 (Fig. 8d).
In the mirror states, the modified device prepared with the TiO2 nanoparticles of 5~10 nm shows similar transmittance with those of 40 and 100 nm (Fig. 1a c).
The optical contrast of the modified device prepared with 5 10 nm TiO2 nanoparticles decreases from 48 to 35% after 1500 cycles (Fig. 5a).
In the black states, the modified device prepared with the TiO2 nanoparticles of 5~10 nm shows the maximum transmittance of 15% and decreases to 10% when increasing the size of TiO2 nanoparticles to 100 nm (Fig. 1a c).
The decrement rates of optical contrasts of 33 and 37% are obtained after 1500 cycles for modified device prepared with precursor concentrations of 1 3 and 1 4, respectively (Fig. 10c, d), which are higher than those prepared with precursor concentration of 1 2 (Fig. 5a).
Different switching times were measured for devices modified with TiO2 nanoparticles of different sizes, with the modified device prepared with 5~10 nm TiO2 nanoparticles exhibiting the shortest switching time (6 s for coloration and 20 s for bleaching) between coloration and bleaching processes.
