## 3 Results & Discussion  
The images in Figure 3a depict the front and rear of the separated cells obtained using laser scribing. Figure 3b shows the conversion power (P\({}_{\text{M}}\)) distribution of 20 separated cells. The average P\({}_{\text{M}}\) of the separated cells was 1.014 \(\pm\) 0.01 W. The inset of Figure 3b shows the I-V curve of a champion cell. The value of the P\({}_{\text{M}}\) decreased about 1.7% compared to the value of the P\({}_{\text{M}}\) without electrical losses. This phenomenon is expected to reduce the P\({}_{\text{M}}\) due to laser scribing damage [15]. To minimize P\({}_{\text{M}}\) loss, we will optimize the laser scribing process. Next, we fabricated 17 connected shingled strings using the ECA dispensing and curing process. Because of the top of the front busbar electrode and the back electrode of the next separated cell, there is no busbar electrode on the top of the shingled string, as shown in Figure 4a. Therefore, shingled-type PV modules exhibit a larger P\({}_{\text{M}}\) than conventional PV modules in the same installation area. To analyze the damage to the shingled strings, we measured the EL images with an applied current injection of 0.9 A in Figure 4b. The EL image shows the absence of critical cracks and damage in the interconnection process. Figure 3: (**a**) Photo images of the front and rear sides of the separated cells and (**b**) the conversion power distribution of 20 separated cells. Inset: I-V curve of a champion cell. Figure 2: Schematic of the shingled-type lightweight glass-free solar module. To optimize the conversion power of the shingled-type strings, we adjusted the amount of dispensed ECA. In our previous work, a 0.17 mm overlap width between the top and bottom separated cells for the interconnection was found to yield the best \(\mathrm{P_{M}}\)[15]. The amount of dispensed ECA was adjusted by the rounds per minute (RPM) control of the dispenser to optimize the \(\mathrm{P_{M}}\) of the strings. When the RPM of the dispenser was 100, 120, and 140, the dispensed amounts of ECA were 16, 24.8, and 32.4 mg, respectively. We found that the fill factor and \(\mathrm{P_{M}}\) values of the string were optimized when the dispensed amount of ECA was 24.8 mg in Figure 4c. The cells interconnected with ECA formed a circuit in which two shingle-diode models representing the separated cell were connected in series [19]. Consequently, the serial resistance of the ECA interconnection was added to the shingled strings, making it a critical factor for optimizing the \(\mathrm{P_{M}}\). Figure 4d shows the \(\mathrm{P_{M}}\) distribution of 15 shingled-type strings. The average \(\mathrm{P_{M}}\) of shingled-type strings was 16.64 \(\pm\) 0.57 W. The inset of Figure 4d shows the I-V curve of a shingled-type string. Compare with the I-V curve of separated cell in Figure 3b, the value of short circuit current (\(\mathrm{I_{SC}}\)) and fill factor (FF) decreased by approximately 0.11 A and 0.009. The value of the \(\mathrm{P_{M}}\) decreased about 4.5% compared to the value of the \(\mathrm{P_{M}}\) without electrical and optical losses. In case of conventional PV modules with metallic wire interconnections, the \(\mathrm{P_{M}}\) reduction rate is about 4.8% [20]. We fabricated a 1040 mm \(\times\) 965 mm shingled-type PV module with an Al honeycomb structure using 17 interconnected strings, as shown in Figure 5a. We measured EL images with an applied current injection of 3 A to analyze the damage to the PV module, as shown in Figure 5b. The EL image demonstrates the absence of critical cracks or damages during the fabrication of the shingle-type PV module with an Al honeycomb structure. Figure 5c shows the I-V curves of the shingle-type PV module. We achieved a \(\mathrm{P_{M}}\) of 195.84 W at an area of 1.004 m\({}^{2}\) and solar-to-power conversion efficiency of 19.5% for the best PV module. In our shingled-type PV module, we used 12 string arrays with 204 pieces of separated cells.