Determination of energy band diagram and charge carrier mobility of white emitting polymer from optical, electrical and impedance spectroscopy

2015 ◽  
Vol 159 ◽  
pp. 134-138 ◽  
Author(s):  
M.A. Mohd Sarjidan ◽  
H.A. Mohd Mokhtar ◽  
W.H. Abd. Majid
2019 ◽  
Author(s):  
Mohd Taukeer Khan ◽  
Manuel Salado ◽  
Abdullah R. D. Almohammedi ◽  
Samrana Kazim ◽  
Shahzada Ahmad

<p>The electron and hole selective contact (SC) play a pivotal role in the performance of perovskite solar cells. In order to separate the interfacial phenomenon from bulk, the influence of charge SC was elucidated, by means of impedance spectroscopy. The specific role played by TiO<sub>2</sub> and <i>Spiro-OMeTAD</i> as electron and hole SC in perovskite solar cells was investigated at short circuit condition at different temperatures. We have probed MAPbI<sub>3</sub> and (FAPbI<sub>3</sub>)<sub>0.85</sub>(MAPbBr<sub>3</sub>)<sub>0.15 </sub>and elucidated parameters such as charge carrier mobility, recombination resistance, time constant and charge carrier kinetics in perovskite layer and at the interface of perovskite/SC. Charge carrier mobility in mixed perovskite was found to be nearly two order of magnitude higher as compared to MAPbI<sub>3</sub>. Moreover, the carrier mobility in devices with only electron SC was found to be higher as compared only hole SC. The charge accumulation at TiO<sub>2</sub>/perovskite/<i>Spiro</i>-OMeTAD interfaces were studied via frequency dependent capacitance, revealing higher charge accumulation at perovskite/S<i>piro</i>-OMeTAD than at TiO<sub>2</sub>/perovskite interface. By performing varying temperature frequency dependent capacitance measurements the distribution of density of state within the bandgap of the perovskites, the emission rate of electrons from the trap states and traps activation energy was determined. </p>


2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Rafał Antoni Bogaczewicz ◽  
Ewa Popko ◽  
Katarzyna Renata Gwóźdź

Recently it has been found that the heterostructures of n-ZnO/p-Si are promising photovoltaic alternatives to silicon homojunctions. It is well known that the energy band diagram of a heterostructure is crucial for the understanding of its operation. This paper analyzes the ZnO/p-Si heterostructure band by using free AMPS-1D computer program simulations. The obtained numerical results are compared with theoretical calculations based on the depletion region approximation model and the Poisson’s equation for electric potential. The results of the simulation are also compared with the experimental C-V characteristics of the test n-ZnO/p-Si heterostructure. The simulated C-V characteristics is qualitatively consistent with the experimental C-V curve, which confirms the correctness of the determined band diagram of the n-ZnO/p-Si heterostructure.


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