Deep Impact of the n-c-Si Defect Density on Heterojunction with Intrinsic Thin Layer Solar Cells

Authors Z. Dahlal1 , F. Hamdache1 , D. Rached1 , W.L. Rahal2,3

1Laboratoire de Physique des Plasmas, Matériaux Conducteurs et Leurs Applications,U.S.T.O.M.B. – B.P. 1505, El M’naouar, Oran, Algérie

2Laboratoire d’Analyse et d’Application des Rayonnements, U.S.T.O.M.B. – B.P. 1505, El M’naouar, Oran, Algérie

3Département de Physique, Faculté des Sciences Exactes et de l’Informatique, Université Abdelhamid Ibn Badis de Mostaganem, Algérie

Issue Volume 13, Year 2021, Number 6
Dates Received 16 January 2021; revised manuscript received 01 December 2021; published online 20 December 2021
Citation Z. Dahlal, F. Hamdache, D. Rached, et al., J. Nano- Electron. Phys. 13 No 6, 06001 (2021)
PACS Number(s) 73.61.Jc, 71.20.Mq, 88.40.jj, 88.40.hj
Keywords HIT solar cells, Silicon (58) , Defect density, SCAPS-1D (21) , Current density-voltage (J-V) characteristic.

In this work, a Heterojunction with Intrinsic Thin layer (HIT) n-c-Si solar cell: Indium Tin Oxide (ITO)/hydrogenated p-doped amorphous silicon (p-a-Si:H)/hydrogenated intrinsic polymorphous silicon (i-pm-Si:H)/n-doped crystalline silicon (n-c-Si)/Aluminum (Al) has been optimized. Using solar cell capacitance simulator (SCAPS-1D), we have studied the effect of defect density in the bulk (Nt) and at the surface (Nss) of the n-c-Si active layer on the current density-voltage (J-V) characteristic (open-circuit voltage, short-circuit current density, Fill Factor and efficiency). To calculate the values of Nss, we have taken the average between the density of states Gmg located in the band gap (U-shaped model) and the total density of states Ntot (Urbach tails) that we have multiplied by the thickness of the defective layer. We have shown that for a defective surface thickness of 32 Å between hydrogenated polymorphous silicon and crystalline silicon (i-pm-Si:H/n-c-Si), the density of states Gmg located in the band gap and the density of states Ntot at Urbach tails must be equal to 3.51017 cm – 3 and 2.81017 cm – 3, respectively (using U-shaped model). We conclude that the surface of the active layer must be passivated so as to have Nss less than 1011 cm – 2. Then, the lifetime of the minority carriers in the active layer (n-c-Si) must be greater than 1 ms. Indeed, an efficiency of 22.08 % was obtained for Nss = 1010 cm – 2,  = 5 ms.

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