Photovoltaic Device Application of a Hydroquinone-Modified Conductive Polymer and Dual-Functional Molecular Si Surface Passivation Technology

Abstract

In the last decades, the conductive polymer PEDOT:PSS has been introduced in Si-based hybrid solar cells, gaining noticeable research interest and being considered a promising candidate for next generation solar cells which can achieve both of low manufacturing cost and high power conversion efficiency. This study succeeded in improving the electrical conductivity of PEDOT:PSS to 937 S/cm through a simple process of adding hydroquinone (HQ) to the pristine PEDOT:PSS solution. The results also showed that the addition of HQ to PEDOT:PSS(HQ-PEDOT:PSS) could not only dramatically improve the conductivity but also well-sustain the work function characteristics of PEDOT:PSS by promoting the formation of more continuous conductive-PEDOT channels without removing the insulating PSS. In this report, we reveal that the application of the HQ-PEDOT:PSS to the Si/PEDOT:PSS HSC could significantly improve the short-circuit current and open-circuit voltage characteristics to increase the power conversion efficiency of the HSCs compared to the conventional approaches. Moreover, we also treated the Si surface with the organic monomer, benzoquinone (BQ) to (1) passivate the excess Si surface defect states and (2) to improve the properties of the Si/PEDOT:PSS interface. We show that BQ treatment is able to dramatically increase the minority carrier lifetime induced by effective chemical and field-effect passivation in addition to enhancing the wettability of the Si surface with the PEDOT:PSS solution. As a result, the power conversion efficiency was increased by 10.6% by introducing HQ and BQ into the fabrication process of the Si/PEDOT:PSS HSC.

Asymmetric TMO–Metal–TMO Structure for Enhanced Efficiency and Long-Term Stability of Si-Based Heterojunction Solar Cells

“…To validate the assumption, the current density–voltage diode equation (Equation (1)) was applied to the J–V curve ( Figure 7 a) obtained from the fabricated HSCs under the dark condition, and the saturation current ( J 0 ) was calculated from Equation (2): where A is the contact area; A * is the effective Richardson constant (120 Acm −2 K −2 for n-type silicon); T is 25 °C (298 K); k is the Boltzmann constant; n is the ideality factor; J 0 is the reverse saturation current density; V bi is the barrier height in Schottky diodes (i.e., a built-in-potential); and q is the elementary charge. In this way, V bi was extracted and presented in Figure 7 c [ 37 ]. In Figure 7 c, it can be seen that the calculated V bi increased with the increasing top VO thickness.…”

“…The increase in the V oc observed in Figure 7 c reflects and confirms the influence of V bi on the solar cell parameters. Furthermore, the higher V bi induces an imbalance in electron and hole concentrations owing to the strengthened field-effect at the TMO/Si interface—this is expected to reduce the carrier loss caused by the Shockley–Read–Hall recombination ( R SRH ) at the Si surface as expressed in Equation (3); this, in turn, extends the of the device [ 37 , 38 ]. where n 1 and p 1 are the densities of the electrons and holes in the bulk, respectively; n s and p s are the densities of the electrons and holes at the surface, respectively; v th is the thermal velocity; E c and E v are the conduction and valance band energies, respectively; D it is the density of the interface states; and σ n and σ p are the energy-dependent capture cross sections of the holes and electrons, respectively.…”

“…where A is the contact area; A* is the effective Richardson constant (120 Acm −2 K −2 for n-type silicon); T is 25 • C (298 K); k is the Boltzmann constant; n is the ideality factor; J 0 is the reverse saturation current density; V bi is the barrier height in Schottky diodes (i.e., a built-in-potential); and q is the elementary charge. In this way, V bi was extracted and presented in Figure 7c [37]. In Figure 7c, it can be seen that the calculated V bi increased with the increasing top VO thickness.…”

“…The increase in the V oc observed in Figure 7c reflects and confirms the influence of V bi on the solar cell parameters. Furthermore, the higher V bi induces an imbalance in electron and hole concentrations owing to the strengthened field-effect at the TMO/Si interface-this is expected to reduce the carrier loss caused by the Shockley-Read-Hall recombination (R SRH ) at the Si surface as expressed in Equation (3); this, in turn, extends the τ e f f of the device [37,38].…”

Preparation of ternary polyaniline@CuO−zeolite composite, discussion of characteristics, properties and their applications in supercapacitors and cationic dye adsorption

“…Conducting polymers (CPs) are generally conjugated systems that consist of an overlapped set of molecular orbitals, which give rise to the mobility of charge carriers along the chain 1 . From a devices point of view, CPs have many applications including sensors, 2 microwave‐ and radar‐absorbing materials, 3 rechargeable batteries, 4 thin film transistors, 5 electronic and bio‐electronic components, 6 light‐emitting diodes, 7 solar cells 8 and photodetectors 9 . The synthesis of conducting hybrid material based on inorganic materials or metal−polymer composites at the nanosized level has generated more sensitive applications due to the synergetic properties of the two combined materials 10 .…”