Conduction Band Offset Effect on the Cu2ZnSnS4 Solar Cells Performance

Ahmed Latrous , Ramdane Mahamdi (1) , Naima Touafek , Marcel Pasquinelli (2)

1 UMC - Université Frères Mentouri – Constantine 1 = Constantine 1 – Frères Mentouri University
2 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence

Among the causes of the degradation of the performance of kesterite-based solar cells is the wrong choice of the n-type buffer layer which has direct repercussions on the unfavorable band alignment, the conduction band offset (CBO) at the interface of the absorber/buffer junction which is one of the major causes of lower VOC. In this work, the effect of CBO at the interface of the junction (CZTS/Cd(1-x)ZnxS) as a function of the x composition of Zn with respect to (Zn+Cd) is studied using the SCAPS-1D simulator package. The obtained results show that the performance of the solar cells reaches a maximum values (Jsc = 13.9 mA/cm 2 , Voc = 0.757 V, FF = 65.6%, ɳ = 6.9%) for an optimal value of CBO =-0.2 eV and Zn proportion of the buffer x = 0.4 (Cd0.6Zn0.4S). The CZTS solar cells parameters are affected by the thickness and the concentration of acceptor carriers. The best performances are obtained for CZTS absorber layer, thichness (d = 2.5 µm) and (ND = 10 16 cm-3). The obtained results of optimizing the electron work function of the back metal contact exhibited an optimum value at 5.7 eV with power conversion efficiency of 13.1%, Voc of 0.961 mV, FF of 67.3% and Jsc of 20.2 mA/cm 2 .

Mots clés: absorber layer; buffer layer; CBO; Cd(1-x)ZnxS; CZTS; interface; SCAPS-1D; solar cell; absorber layer

Domaines: Sciences de l'ingénieur [physics]

Ahmed Latrous, Ramdane Mahamdi, Naima Touafek, Marcel Pasquinelli. Conduction Band Offset Effect on the Cu2ZnSnS4 Solar Cells Performance. Annales de Chimie - Science des Matériaux, 2021, 45, pp.431 - 437. ⟨10.18280/acsm.450601⟩. ⟨hal-03602287⟩