Analysis and optimization of alloyed Al-p⁺ region and rear contacts for highly efficient industrial n-type silicon solar cells

Abstract

This paper aims to develop high quality screen-printed Al emitters and improve the interface condition of rear contacts in industrial silicon solar cells.

Correlation between Boron–Silicon Bonding Coordination, Oxygen Complexes and Electrical Properties for n-Type c-Si Solar Cell Applications

“…This leads to the change in the electrical properties and affects the output characteristics of the solar cell. The electrical properties of the p + diffused layer, such as effective lifetime, iV oc and saturation current are obtained by the following formula [23,24].…”

“…Figure 3 analyzes the electrical properties of the p + diffused emitter by the relative ratio of the activated boron (binding energy (BE) = 187.8 eV) and interstitial defect boron (BE = 186.7 eV) peaks, obtained through the previous XPS analysis. The ratio of the activation/interstitial boron peaks shown on the x-axis is 0.58, 1.81, 1.89 and 2.24, and the R sheet of the p + diffused layers are 70, 80, 100 and 200 ohm/sq, respectively.The electrical properties of the p + diffused layer, such as effective lifetime, iV oc and saturation current are obtained by the following formula[23,24].…”

An assessment on crystallization phenomena of Si in Al/a-Si thin films via thermal annealing and ion irradiation

“…As a result of both effect, Al tends to migrate into the underlying a-Si layer and eventually replace the whole Si layer, known as layer exchange mechanism. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] Therefore, the crystallization of Si for both set of samples (set-A & set-B) has been found at higher annealing temperature and found to increase with the increasing of annealing temperatures.…”

“…Al is successful in bringing out the crystallization at very low temperature, as it is a post-transition metal, which constitutes a simple eutectic binary system with Si, and is not involved in the formation of any compound phases via AIC. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] The AIC process in various Al/a-Si systems has been extensively investigated in the last decade because of applications of poly-Si in low-temperature production of high-performance solar cells, at-panel displays, and high-density data storage devices. Many groups investigated the impact of different parameters such as Al and Si layer thicknesses, layer orders, layer interface types, and Al to Si content ratios on the AIC process.…”