Functions of Interfacial Materials

Generally, the functions of an interfacial layer include, but are not limited to  

1 Enhancing Charge Extraction at Electrodes and Tuning Energy Alignment 

In PSCs, a barrier height of several tens of mV may cause severe charge accumulation. Ohmic contacts can be formed at both electrodes by inserting an appropriate interfacial layer between the active layer and electrodes to shift the WF of the electrodes to ideal values, from which the Vdc can reach the upper limit, because the magnitude of Voc limited by the difference between the effective WF of the HCE and ECE in PSCs. Under the condition of Ohmic contact, the charge extraction at both electrodeswill be accelerated and the recombination loss will be reduced benefiting from both effects, enhanced/sc is achievable. 

2 Controlling Electrode Polarity and Charge Extraction Selectivity 

Electron colleting layer Active Layer Hole collecting layer Hole collecting electrode Transparent substrate 

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