She made a cameo appearance in the 2015 romance web drama Imaginary Cat as Jung Soo-In.

[20][21] On February 21, 2019, Solar launched her personal YouTube channel called "Solarsido" to celebrate her 29th birthday (Korean age).

She made her official solo debut with the single "Spit It Out" which was released with a music video on April 23, 2020.

[25] On May 12, 2021, it was announced that Solar joined Gummy, Lee Seung-chul, Bae Cheol-soo, Jung Jae-hyung, Kim Hyun-chul, and Winner's Kang Seung-yoon on KBS audition program The Song We Loved, New Singer show as a judge, marking her first time as a judge in a singing/audition program.

[26] On July 20, 2021, it was announced that Solar joined JTBC's Poongryu – Battle Between the Vocalist as a judge alongside Song Ga-in, Lena Park, Sung Si-kyung, Kim Jong-jin, Lee Juck, and 2PM's Jang Wooyoung.

[28] During her time as a cast member and guest star, Solar recorded the best minute ratings of 9.7%,[29] 10.6%,[30] 10.8%,[31] and 12.7%[32] in multiple episodes, proving her power as a variety show personality and entertainer.

NME critic Rhian Daly gave the album a 4 out of 5 score, and stated "容: FACE captures Solar's energetic, bright and breezy personality well.

The rap verse on "Honey" is a particular highlight that showcases her dynamism, while the mini-album as a whole pops with little vocal details that subtly elevate the songs.

Solar was known as Fully Paid Fairy for obtaining 44 candles in 3 different episodes, making history as the first and only cast member to achieve this.

[40] On December 21, 2022, it was announced that Solar will be singing in the title song "Paradise" for Channel S' DJ Survival competition show WET!

[42] On June 6, 2023, Solar was announced to join as the last judge for the show 2023 Veiled Musician alongside Paul Kim, Highlight's Yang Yo-seob and Son Dong-woon, Yang Da-il, Melomance's Jeong Dong-hwan, Sole, and Shin Yong jae.

She will be joined alongside Red Velvet's Wendy, BTOB's Seo Eunkwang, NU'EST's Baekho, and Lee Seok-hoon.

She is recognized for her extraordinary vocal skills, and will be expected to give guidance in stage and performance, as well as insight as professional idol.

[45] On March 21, 2024, Solar was announced as one of the coaches for KBS's new Global Idol Debut Project Make Mate 1.

She will be joined by singer Lim Han-byul, vocal teacher Kim Seongeun, dancer WE DEM BOYZ In-gyu and Bata, and rapper Hanhae.

Solar Emotion Part.7 was released on January 18, 2023, at 6 pm through various music sites and limited cassette tape album which features the song.

[47][48] IZM (Korea's biggest music website) critic Jang Junhwan stated "Solar successfully conveys the aspects of redrawing the charm of the original song and reinterpreting it in her own color.

On April 8, 2024, Solar announced her comeback with her second extended play (EP) titled Colours, 2 years and 1 month after the release of her first mini album 容: Face.

[51] On May 7, 2024, Solar announced that she will hold her second concert Colours with its first performance held in Blue Square Mastercard Hall in Seoul on June 1–2, 2024.

Daxed also highlights Colors as a rare example of diverse LGBTQ+ representation in K-pop, and praised the song for its joyous and defiant sound and tone with its lyrics "Look in the mirror... And say it, I'm sick, so bad, louder, louder, I'm sick, I'm hot, I'm gorgeous" [56] On April 6, 2022, EMK Musical announced that Solar will be starring in the 3rd season of the musical Mata Hari alongside Ock Joo Hyun as the titular character.

[58] One review stated that they were attracted to Solar's style, as her clear notes and drawn tones exceeded expectations, and she "tore up" the stage.

Another highlighted song was the final number of Act 2 "One Last Time" in which Mata Hari said goodbye to her loved ones, proved Solar's skill again as Mamamoo's vocalist once again.

[62] On November 15, 2023, Solar was cast in the Korean version of Notre-Dame de Paris, scheduled to run from January 24 to March 24, 2024.

"[64] Sports Q reporter Na Hyein also adds the perfection of her casting and vocal prowess, stating "With her unrivaled explosive vocal range, dance skills that captivate the audience, and enchanting eyes and gestures, Solar's talents all point to Esmeralda, there could not be a more perfect casting than this.

On October 14, 2024, EMK Musical officially announced Solar as a returning cast member for the fourth season of Mata Hari, premiering on December 5, 2024, until March 2, 2025.

[68] On October 5, 2024, it was announced that Solar would be returning to acting in the supernatural thriller "Gory: A Horror Tale" directed by director Hong Won-ki.

[69] In 2016, Solar was ranked as the 18th and 10th most popular K-pop idol according to Women in the age range of 19–29 years old in annual surveys conducted by Gallup Korea.

She was chosen for her "clean skin" and "bright and lively energy" that go well with the brand image that pursues bare-faced confidence.

[74] On May 14, 2021, Solar was selected as one of the musicians and content creator collaborating with Samsung to commemorate the launch of Samsung's Galaxy Book series with a 'Galaxy Live Quiz Show' (Gala Show), as well as promotional advertisements alongside fellow musician and content creator Gray.

The campaign aimed to help girls of their rights to protection for matters such as early marriage, school interruption, and reproductive diseases.