The formal structure above, combine

The formal structure above, combined with the back surface field passivation, increased the efficiency of PEDOT:PSS/ c-si solar cells to 12.1%. By testing the external quantum efficiency of the battery, we can not only calculate the short-circuit current density, but also see the quantum efficiency of the battery in the absorption of photons of different wavelengths. As can be seen from figure 4.5 (b), the external quantum efficiency of the formal structure PEDOT:PSS/ c-si battery is gradually reduced from 600 nm to 1200 nm. Even if surface and field passivation is used to reduce the carrier composite loss, the short-circuit current density is still lower than 30 mA/cm2. In the formal structure of the PEDOT:PSS/ c-si battery, PEDOT:PSS serves as the window layer and the transmitter layer for the transmission hole. PEDOT: the transmittance and parasitic absorption of PSS have great influence on the photovoltaic performance of the whole cell. In order to characterize the parasitic absorption of PEDOT:PSS in PEDOT:PSS/ c-si battery, the absorption spectrogram of PEDOT:PSS film with a thickness of 100 nm was measured. The results are shown in FIG. 4.7 (a). Figure 4.7 (b) compares the extinction coefficients of PEDOT:PSS film and ITO film, and the results show that PEDOT:PSS film has stronger parasitic absorption than ITO film in visible and near infrared spectral regions. The formal structure of PEDOT:PSS/ c-si solar cells in the range of 600-1200 nm is mainly due to the parasitic absorption of PEDOT:PSS films.