Regulation Of Quantum Interference On Radiation Recombination In Quantum Photovoltaic Cell

The efficiency limit of Shockley-Quisser caused by various intrinsic reverse losses in the process of photon exciton transport in photovoltaic devices is its low cost and widely used bottlenecks,such as Kirchhoff radiation loss,low energy photons that cannot be fully absorbed,and thermal loss,Carnot loss and exciton radiation recombination during transportation.n view of this,this paper studies the theoretical model of the action of light and matter extracted from the photovoltaic device,a macro device,and conducts research work on how to suppress radiation recombination and increase the absorption rate of low-energy photons to achieve efficient photoelectric conversion,as follows:1?The regulation mechanism of radiation recombination in a quantum photovoltaic cell system containing three electron donors was studied.Considering whether there is coupling between the three electron donors,the effects of external temperature difference,band gap difference and coupling strength on radiation recombination are analyzed.The results are as follows:(1)It was found that under the uncoupled condition,the difference of temperature difference and energy gap between donors had an inhibiting mechanism on the radiation recombination rate,but the difference of energy gap between donors and receptors had a promoting effect.Under the coupling condition,the temperature difference and the energy gap between the donor and the receptor have the promoting mechanism to the radiation recombination rate,while the energy gap between the donor has the inhibiting effect.(2)The radiation recombination rate under coupling condition is generally lower than that under uncoupled condition,and the effect of coupling intensity on the radiation coincidence rate is discussed.This reveals that the quantum interference effect plays an important role in achieving a small radiation recombination rate.2?The regulation mechanism of quantum interference effect on the recombination rate of exciton radiation in quantum photovoltaic cells is studied.It is discussed that the effects of Fano interference between transitions at different energy levels,the difference in energy gap between donor molecules and acceptor molecules,and the absorbed photon wavelength on the recombination of exciton radiation.The results are as follows:(1)It is found that when the transition rate between energy levels is close to the same,Fano quantum interference is the strongest,which can suppress the radiation recombination rate to the greatest extent.(2)The better inhibition effect of the radiation recombination rate is due to the higher transport efficiency of photoelectrons when the energy gap between the donor and the receptor is small.(3)The smaller radiation recombination rate is caused by the faster transfer of photoelectrons with higher kinetic energy to the load when short-wave high-frequency photons are absorbed.3?The control mechanism of the quantum energy and photoelectric conversion efficiency of the quantum energy of quantum dot photovoltaic cells is studied.Since the mature doping technology can effectively absorb low-energy solar photons,we use a multilevel light and matter interaction system to simulate doped quantum dot solar cells.And the contribution of photons in the visible spectrum [0.5e V,1.25 e V ] range to the quantum efficiency and photoelectric conversion efficiency of the system is discussed.The results are as follows:(1)The energy level structure of the two sub-bands can absorb more low-energy photons,which can maximize the quantum efficiency and photoelectric conversion efficiency of quantum dot photovoltaic cells.However,the higher ambient temperature will affect the transport efficiency of photo-generated carriers.(2)Comparing the contributions of two different band gap energies to the quantum efficiency of the system,the results show that the narrower lower band absorbs more low-energy photons than the upper band,resulting in more carrier output to the load end,resulting in a higher quantum system efficiency.(3)In the same solar absorption spectral region,the photoelectric conversion efficiency obtained is higher than Shockley and Quisser efficiency,and the efficiency limit at room temperature is also greater than the 63% photoelectric conversion efficiency of Luque and Marti.4?The effect of quantum interference on the photoelectric conversion efficiency of degenerate/non-degenerate double-band quantum dot photovoltaic cell system is studied.Considering a quantum dot photovoltaic cell system with two sub-bands,the effect of quantum interference between energy bands on the photoelectric conversion efficiency under degenerate and non-degenerate conditions is discussed.The results are as follows:(1)Under the condition that the quantum dot photovoltaic cell system contains two degenerate intermediate energy levels,the strong quantum coherence effect between the upper band gap has a positive effect on the photoelectric conversion efficiency of the system,while the quantum coherence effect between the lower band gap has a photoelectric effect.The conversion efficiency has a negative effect;the lifetime of the photo-generated carriers in the intermediate energy level has a linear effect on the photoelectric conversion efficiency.(2)When the two intermediate sub-bands are in a non-degenerate condition,the photoelectric conversion efficiency of the quantum dot photovoltaic cell system is smaller than in the case of degeneracy,indicating that the degenerate intermediate band gap is more beneficial to the photoelectric conversion efficiency of the system.The above results show that the quantum control of exciton radiation recombination in quantum dot photovoltaic cells and the full use of the quantum interference effect generated between the band gaps can accurately control the photogenerated excitons,which can effectively improve the photoelectric conversion efficiency.This not only has a positive theoretical significance for gradually achieving the on-demand design goals of quantum dot photovoltaic cells,but also has a positive significance for enhancing the overall competitiveness of China's photovoltaic industry.