Comparison between textured SnO2:F and Mo contacts with the p-type layer in p–i–n hydrogenate amorphous silicon solar cells by forward bias impedance analysis

Abstract

In this paper we compare the performance of the textured SnO 2 :F and Mo contacts with the p-type layer in p-in hydrogenate amorphous silicon (a-Si:H) solar cells. We use standard current-voltage (I-V) electrical characterization methods coupled with forward bias small signal impedance analysis. We show the efficacy of this technique to determine the effective carrier lifetime in photovoltaic cells. We show that such effective lifetimes are indeed directly connected to the respective dark diode saturation currents. We also find that the effective lifetime is constant with the temperature in the 0-70°C range and it is significantly better for the solar cell with Mo diode contact. This also explains well the higher open circuit voltage V oc found under illumination in the Mo/p-in cell compared to the SnO 2 :F/pi-n one.

Role of electric field and electrode material on the improvement of the ageing effects in hydrogenated amorphous silicon solar cells

“…To test such concept we have performed reverse bias stress experiments in samples in which the TCO layer in contact with the p-type a-Si: H film has been replaced by a Mo film, in cells realized as described in the previous section. The use of Mo can give some advantage for the p-type a-Si:H/metal contact resistance and for the solar cell carrier lifetime (compared to FTO) [10,11], and it may be advantageous to fabricate a-Si:H solar cells on flexible substrates [12], and to realise plasmonic light trapping [21]. Fig.…”

“…In the case of the cells with Mo bottom contact the efficiencies were typically about 5% with open-circuit voltage of 0.85 V, short-circuit current densities of 12 mA/cm 2 and fill factor of 47%. The differences between these two types of cells are discussed in detail in references [10][11][12] and they are attributed to differences in substrate texture and photocarrier lifetime.…”

Influence of pin Amorphous Silicon Stack Deposition Sequence on Solar Cell Performance and Degradation

“…According to literature reports, in the forward bias condition, the carrier lifetime at the Mo/ptype a-Si:H interface is longer than that at the transparent conductive oxide (TCO)/p-type a-Si:H interface. 18,19 In other words, the carrier recombination rate in the former is lower than that in the latter. It was also reported that the ITO electrode usually forms ohmic contact with both p-type and n-type a-Si:H films.…”

Preparation of Nc-Si/A-Sio2 Multi-Layer Thin Film Specimens for TEM Cross-Section Observation by Cryo Argon Ion Slicing

“…Hence, the analyses of size, structure and morphology of the thin layers are important to fulfil the above said requirements. Recently, large efforts have been put on the manufacturing of thin films to improve the efficiency of amorphous and microcrystalline silicon based solar cells [1][2][3][4][5][6]. The main intention on the development of such materials in solar industry (3 rd generation of solar cells) is to reduce the usage of materials and deposition costs, and also to increase the efficiency of the photovoltaic devices.…”