Influence of Urbach Energy, Temperature, and Longitudinal Position in the Active Layer on Carrier Diffusion Length in Perovskite Solar Cells

Abstract

The diffusion length of charge carriers in the active layer of a perovskite solar cell (PSC) of the structure Glass/PEDOT: PSS/ CH 3 NH 3 PbI 3 /PC60BM/Al is modelled. It is found that the diffusion length depends on the position x in the active layer measured from the PEDOT: PSS interface, Urbach energy and temperature. By varying the voltage in the range from zero to V oc , it is shown that the dependence of diffusion length on the position x in the active layer reduces at higher voltage. The combined influence of applied voltage and temperature on the diffusion length of charge carriers is investigated and it is found that in the low voltage range the diffusion length is temper-ature independent, but it becomes significantly temperature dependent at higher voltages. Also, it is found that the diffusion length decreases as the applied voltage increases and this reduction becomes much more significant at higher voltage and temperatures. The combined influence of applied voltage and Urbach energy on diffusion length of charge carriers reveals that the diffusion length decreases when both the applied voltage and Urbach energy increase. However, the reduction in the diffusion length due to the increase in Urbach energy becomes less significant at higher voltage.

Influence of Interfacial Traps on the Operating Temperature of Perovskite Solar Cells

“…The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has grown drastically during recent years, and a PCE of higher than 23% for single PSCs and about 28% for perovskite/silicon tandem solar cells have been reported recently [1,2,3,4,5,6]. One of the factors that can influence the PCE of solar cells is their temperature during the operation or the operating temperature T. It is well-known that if the operating temperature decreases then the diffusion length of charge carriers and PCE of PSCs increase for T > 200 K [7,8,9]. A high operating temperature may lead to the degradation in PSCs due to the decomposition of the active layer.…”

Single‐Junction Organic Photovoltaic Cells with Approaching 18% Efficiency

“…The crystalline property implies a different degree of molecular ordered packing, which is correlated to the Urbach energy. [45,46] Here, the crystalline property of the three blend films is affected by the polymer donor PBDB-TF as it has a strong self-aggregation effect. [47,48] As a result, the Urbach energy of all blend films is similar ( Figure S8, Supporting Information).…”

Influence of Interfacial Traps on the Operating Temperature of Perovskite Solar Cells

“…where, ℎ , − , ℎ , − , ℎ , − and ℎ , − are used as a function of given in Eqs. (6) - (8) and the rate of tail state recombination is calculated by solving Poisson and driftdiffusion equations. We solve Eq.…”

“…First, we start with an initial temperature T to solve the drift-diffusion equations and calculate the heat transfer coefficients in Eqs. (6) - (8). Then, by substituting back these calculated , ℎ , − , ℎ , − , ℎ , − and ℎ , − in Eq.…”

“…The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has grown drastically during last years, and a PCE of higher than 23% has been reported recently [1][2][3][4][5]. One of the factors that can influence PCE of solar cells is their temperature during the operation or the operating temperature T. It is well-known that if the operating temperature decreases then the diffusion length of charge carriers and PCE of PSCs increase for T>200 K [6][7][8]. A high operating temperature may lead to the degradation in PSCs due to the decomposition of active layer.…”