## 1 Introduction  
The solar industry has been attracting attention as a future energy source, and the demand and supply market for crystalline silicon (c-Si) solar cells has been gradually expanding. However, the maximum efficiency of conventional c-Si solar cell fabrication technology is limited, so it is necessary to study this technology in order to improve its efficiency [1; 2; 3]. Currently, new methods of increasing efficiency involve cell design modifications using selective emitters [4]. In contrast to a conventional single emitter, a selective emitter is a heavily doped region with a large depth of impurity diffusion in the electrode region. In addition, a lightly doped region with a small depth of impurity diffusion is formed in the non-electrode region. A heavily doped region can reduce the contact resistance between the front electrode and the emitter, and it can increase the open-circuit voltage (V\({}_{\text{oc}}\)). However, the recombination velocity increases and the carrier lifetime decreases due to the scattering effect with excessive impurities. In contrast, a lightly doped region reduces the recombination at the surface and offers excellent quantum efficiency characteristics in the short wavelength region. Selective emitter solar cells can increase efficiency by utilizing low-concentration and high-concentration emitters. Among the methods of forming a selective emitter structure, the laser process can be an advantageous alternative for creating doped contacts in solar cells because of its simple fabrication process that avoids the high temperature and photolithography steps in the opening and simultaneously dopes of the base and emitter contacts. An emitter formation process is carried out in a laser doping selective emitter (LDSE) solar cell to diffuse phosphorus (P) into the wafer to form a p-n junction. Next, the laser process step is carried out in the formation area of the selective emitter [5]. The electrode surface is processed using a laser with respect to the area where the electrode should be located.  
A laser-assisted LDSE is capable of offering high output and a high repetition rate; hence, it is possible to achieve high throughput and production. In addition, lasers can create LDSE structures using a one-step process, which is unlike conventional techniques that require multiple steps such as mask deposition, chemical etching, and high-temperature diffusion [6; 7]. This laser process leads to the diffusion of additional P atoms from the phosphorus silicate glass (PSG) layer, which is generated during the doping process, and high doping for already-diffused P atoms. The resistance of the sheet area where the laser process is carried out is less than that of the sheet area where the laser process is not carried out. The University of New South Wales (UNSW) School of Photovoltaics and Renewable Energy Engineering developed a technology for the laser doping of a selective emitter solar cell. As a result of the present research, the contact resistivity between the electrode and silicon wafer generated using the conventional screen printing method was significantly reduced by applying a laser doping selective emitter [8; 9]. This paper is divided into the following sections. First, we studied a weak emitter formed from a POCI\({}_{3}\) (phosphorus oxychloride) tube furnace and determined the different doping profiles. Next, the effect of the laser doping step on the selective emitters was analyzed using the optimized laser parameters. The selective emitter structures were irradiated using a range of laser processing conditions to determine the effects of the laser frequency, wavelength, laser fluence, and laser speed on the dopant profile and diode characteristics. Additionally, the same processes for different laser conditions were performed to achieve a high doping efficiency at a relatively low laser fluence, resulting in reduced laser-induced damages.