Study on the ITO work function and hole injection barrier at the interface of ITO/a-Si:H(p) in amorphous/crystalline silicon heterojunction solar cells

For this study we focused on the front contact barrier height of HIT (ITO/a-Si:H(p)/a-Si:H(i)/c-Si(n)) solar cell. The ITO films with low resistivity of 1.425 × 10 ^-4 Ω cm were deposited by pulsed DC magnetron sputtering as a function of substrate temperature (T _s). There were improvement in Φ _ITO from 4.15 to 4.30 eV and delta hole injection barrier from 0 to 0.129 eV for the HIT solar cell. The results show that the high values of Φ _ITO and the delta hole injection barrier at the front interface of ITO/p-layer lead to an increase of open circuit voltage (V _oc), fill factor (FF) and efficiency (η). The performance of HIT device was improved with the increase of T _s and the best photo voltage parameters of the device were found to be V _oc = 635 mV, FF = 0.737 and η = 14.33% for T _s = 200 °C.